/* jQuery UI Date Picker v3.4.3 (previously jQuery Calendar)
   Written by Marc Grabanski (m@marcgrabanski.com) and Keith Wood (kbwood@virginbroadband.com.au).

   Copyright (c) 2007 Marc Grabanski (http://marcgrabanski.com/code/ui-datepicker)
   Dual licensed under the MIT (MIT-LICENSE.txt)
   and GPL (GPL-LICENSE.txt) licenses.
   Date: 09-03-2007  */
   
;(function($) { // hide the namespace

/* Date picker manager.
   Use the singleton instance of this class, $.datepicker, to interact with the date picker.
   Settings for (groups of) date pickers are maintained in an instance object
   (DatepickerInstance), allowing multiple different settings on the same page. */

function Datepicker() {
  this.debug = false; // Change this to true to start debugging
  this._nextId = 0; // Next ID for a date picker instance
  this._inst = []; // List of instances indexed by ID
  this._curInst = null; // The current instance in use
  this._disabledInputs = []; // List of date picker inputs that have been disabled
  this._datepickerShowing = false; // True if the popup picker is showing , false if not
  this._inDialog = false; // True if showing within a "dialog", false if not
  this.regional = []; // Available regional settings, indexed by language code
  this.regional[''] = { // Default regional settings
    clearText: 'Clear', // Display text for clear link
    clearStatus: 'Erase the current date', // Status text for clear link
    closeText: 'Close', // Display text for close link
    closeStatus: 'Close without change', // Status text for close link
    prevText: '<Prev', // Display text for previous month link
    prevStatus: 'Show the previous month', // Status text for previous month link
    nextText: 'Next>', // Display text for next month link
    nextStatus: 'Show the next month', // Status text for next month link
    currentText: 'Today', // Display text for current month link
    currentStatus: 'Show the current month', // Status text for current month link
    monthNames: ['January','February','March','April','May','June',
      'July','August','September','October','November','December'], // Names of months for drop-down and formatting
    monthNamesShort: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'], // For formatting
    monthStatus: 'Show a different month', // Status text for selecting a month
    yearStatus: 'Show a different year', // Status text for selecting a year
    weekHeader: 'Wk', // Header for the week of the year column
    weekStatus: 'Week of the year', // Status text for the week of the year column
    dayNames: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'], // For formatting
    dayNamesShort: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'], // For formatting
    dayNamesMin: ['Su','Mo','Tu','We','Th','Fr','Sa'], // Column headings for days starting at Sunday
    dayStatus: 'Set DD as first week day', // Status text for the day of the week selection
    dateStatus: 'Select DD, M d', // Status text for the date selection
    dateFormat: 'mm/dd/yy', // See format options on parseDate
    firstDay: 0, // The first day of the week, Sun = 0, Mon = 1, ...
    initStatus: 'Select a date', // Initial Status text on opening
    isRTL: false // True if right-to-left language, false if left-to-right
  };
  this._defaults = { // Global defaults for all the date picker instances
    showOn: 'focus', // 'focus' for popup on focus,
      // 'button' for trigger button, or 'both' for either
    showAnim: 'show', // Name of jQuery animation for popup
    defaultDate: null, // Used when field is blank: actual date,
      // +/-number for offset from today, null for today
    appendText: '', // Display text following the input box, e.g. showing the format
    buttonText: '...', // Text for trigger button
    buttonImage: '', // URL for trigger button image
    buttonImageOnly: false, // True if the image appears alone, false if it appears on a button
    closeAtTop: true, // True to have the clear/close at the top,
      // false to have them at the bottom
    mandatory: false, // True to hide the Clear link, false to include it
    hideIfNoPrevNext: false, // True to hide next/previous month links
      // if not applicable, false to just disable them
    changeMonth: true, // True if month can be selected directly, false if only prev/next
    changeYear: true, // True if year can be selected directly, false if only prev/next
    yearRange: '-10:+10', // Range of years to display in drop-down,
      // either relative to current year (-nn:+nn) or absolute (nnnn:nnnn)
    changeFirstDay: true, // True to click on day name to change, false to remain as set
    showOtherMonths: false, // True to show dates in other months, false to leave blank
    showWeeks: false, // True to show week of the year, false to omit
    calculateWeek: this.iso8601Week, // How to calculate the week of the year,
      // takes a Date and returns the number of the week for it
    shortYearCutoff: '+10', // Short year values < this are in the current century,
      // > this are in the previous century, 
      // string value starting with '+' for current year + value
    showStatus: false, // True to show status bar at bottom, false to not show it
    statusForDate: this.dateStatus, // Function to provide status text for a date -
      // takes date and instance as parameters, returns display text
    minDate: null, // The earliest selectable date, or null for no limit
    maxDate: null, // The latest selectable date, or null for no limit
    speed: 'normal', // Speed of display/closure
    beforeShowDay: null, // Function that takes a date and returns an array with
      // [0] = true if selectable, false if not,
      // [1] = custom CSS class name(s) or '', e.g. $.datepicker.noWeekends
    beforeShow: null, // Function that takes an input field and
      // returns a set of custom settings for the date picker
    onSelect: null, // Define a callback function when a date is selected
    onClose: null, // Define a callback function when the datepicker is closed
    numberOfMonths: 1, // Number of months to show at a time
    stepMonths: 1, // Number of months to step back/forward
    rangeSelect: false, // Allows for selecting a date range on one date picker
    rangeSeparator: ' - ' // Text between two dates in a range
  };
  $.extend(this._defaults, this.regional['']);
  this._datepickerDiv = $('<div id="datepicker_div"></div>');
}

$.extend(Datepicker.prototype, {
  /* Class name added to elements to indicate already configured with a date picker. */
  markerClassName: 'hasDatepicker',

  /* Debug logging (if enabled). */
  log: function () {
    if (this.debug)
      console.log.apply('', arguments);
  },
  
  /* Register a new date picker instance - with custom settings. */
  _register: function(inst) {
    var id = this._nextId++;
    this._inst[id] = inst;
    return id;
  },

  /* Retrieve a particular date picker instance based on its ID. */
  _getInst: function(id) {
    return this._inst[id] || id;
  },

  /* Override the default settings for all instances of the date picker. 
     @param  settings  object - the new settings to use as defaults (anonymous object)
     @return the manager object */
  setDefaults: function(settings) {
    extendRemove(this._defaults, settings || {});
    return this;
  },

  /* Attach the date picker to a jQuery selection.
     @param  target    element - the target input field or division or span
     @param  settings  object - the new settings to use for this date picker instance (anonymous) */
  _attachDatepicker: function(target, settings) {
    // check for settings on the control itself - in namespace 'date:'
    var inlineSettings = null;
    for (attrName in this._defaults) {
      var attrValue = target.getAttribute('date:' + attrName);
      if (attrValue) {
        inlineSettings = inlineSettings || {};
        try {
          inlineSettings[attrName] = eval(attrValue);
        } catch (err) {
          inlineSettings[attrName] = attrValue;
        }
      }
    }
    var nodeName = target.nodeName.toLowerCase();
    var instSettings = (inlineSettings ? 
      $.extend(settings || {}, inlineSettings || {}) : settings);
    if (nodeName == 'input') {
      var inst = (inst && !inlineSettings ? inst :
        new DatepickerInstance(instSettings, false));
      this._connectDatepicker(target, inst);
    } else if (nodeName == 'div' || nodeName == 'span') {
      var inst = new DatepickerInstance(instSettings, true);
      this._inlineDatepicker(target, inst);
    }
  },

  /* Detach a datepicker from its control.
     @param  target    element - the target input field or division or span */
  _destroyDatepicker: function(target) {
    var nodeName = target.nodeName.toLowerCase();
    var calId = target._calId;
    target._calId = null;
    var $target = $(target);
    if (nodeName == 'input') {
      $target.siblings('.datepicker_append').replaceWith('').end()
        .siblings('.datepicker_trigger').replaceWith('').end()
        .removeClass(this.markerClassName)
        .unbind('focus', this._showDatepicker)
        .unbind('keydown', this._doKeyDown)
        .unbind('keypress', this._doKeyPress);
      var wrapper = $target.parents('.datepicker_wrap');
      if (wrapper)
        wrapper.replaceWith(wrapper.html());
    } else if (nodeName == 'div' || nodeName == 'span')
      $target.removeClass(this.markerClassName).empty();
    if ($('input[_calId=' + calId + ']').length == 0)
      // clean up if last for this ID
      this._inst[calId] = null;
  },

  /* Enable the date picker to a jQuery selection.
     @param  target    element - the target input field or division or span */
  _enableDatepicker: function(target) {
    target.disabled = false;
    $(target).siblings('button.datepicker_trigger').each(function() { this.disabled = false; }).end()
      .siblings('img.datepicker_trigger').css({opacity: '1.0', cursor: ''});
    this._disabledInputs = $.map(this._disabledInputs,
      function(value) { return (value == target ? null : value); }); // delete entry
  },

  /* Disable the date picker to a jQuery selection.
     @param  target    element - the target input field or division or span */
  _disableDatepicker: function(target) {
    target.disabled = true;
    $(target).siblings('button.datepicker_trigger').each(function() { this.disabled = true; }).end()
      .siblings('img.datepicker_trigger').css({opacity: '0.5', cursor: 'default'});
    this._disabledInputs = $.map($.datepicker._disabledInputs,
      function(value) { return (value == target ? null : value); }); // delete entry
    this._disabledInputs[$.datepicker._disabledInputs.length] = target;
  },

  /* Is the first field in a jQuery collection disabled as a datepicker?
     @param  target    element - the target input field or division or span
     @return boolean - true if disabled, false if enabled */
  _isDisabledDatepicker: function(target) {
    if (!target)
      return false;
    for (var i = 0; i < this._disabledInputs.length; i++) {
      if (this._disabledInputs[i] == target)
        return true;
    }
    return false;
  },

  /* Update the settings for a date picker attached to an input field or division.
     @param  target  element - the target input field or division or span
     @param  name    string - the name of the setting to change or
                     object - the new settings to update
     @param  value   any - the new value for the setting (omit if above is an object) */
  _changeDatepicker: function(target, name, value) {
    var settings = name || {};
    if (typeof name == 'string') {
      settings = {};
      settings[name] = value;
    }
    if (inst = this._getInst(target._calId)) {
      extendRemove(inst._settings, settings);
      this._updateDatepicker(inst);
    }
  },

  /* Set the dates for a jQuery selection.
     @param  target   element - the target input field or division or span
     @param  date     Date - the new date
     @param  endDate  Date - the new end date for a range (optional) */
  _setDateDatepicker: function(target, date, endDate) {
    if (inst = this._getInst(target._calId)) {
      inst._setDate(date, endDate);
      this._updateDatepicker(inst);
    }
  },

  /* Get the date(s) for the first entry in a jQuery selection.
     @param  target  element - the target input field or division or span
     @return Date - the current date or
             Date[2] - the current dates for a range */
  _getDateDatepicker: function(target) {
    var inst = this._getInst(target._calId);
    return (inst ? inst._getDate() : null);
  },

  /* Handle keystrokes. */
  _doKeyDown: function(e) {
    var inst = $.datepicker._getInst(this._calId);
    if ($.datepicker._datepickerShowing)
      switch (e.keyCode) {
        case 9:  $.datepicker._hideDatepicker(null, '');
            break; // hide on tab out
        case 13: $.datepicker._selectDay(inst, inst._selectedMonth, inst._selectedYear,
              $('td.datepicker_daysCellOver', inst._datepickerDiv)[0]);
            return false; // don't submit the form
            break; // select the value on enter
        case 27: $.datepicker._hideDatepicker(null, inst._get('speed'));
            break; // hide on escape
        case 33: $.datepicker._adjustDate(inst,
              (e.ctrlKey ? -1 : -inst._get('stepMonths')), (e.ctrlKey ? 'Y' : 'M'));
            break; // previous month/year on page up/+ ctrl
        case 34: $.datepicker._adjustDate(inst,
              (e.ctrlKey ? +1 : +inst._get('stepMonths')), (e.ctrlKey ? 'Y' : 'M'));
            break; // next month/year on page down/+ ctrl
        case 35: if (e.ctrlKey) $.datepicker._clearDate(inst);
            break; // clear on ctrl+end
        case 36: if (e.ctrlKey) $.datepicker._gotoToday(inst);
            break; // current on ctrl+home
        case 37: if (e.ctrlKey) $.datepicker._adjustDate(inst, -1, 'D');
            break; // -1 day on ctrl+left
        case 38: if (e.ctrlKey) $.datepicker._adjustDate(inst, -7, 'D');
            break; // -1 week on ctrl+up
        case 39: if (e.ctrlKey) $.datepicker._adjustDate(inst, +1, 'D');
            break; // +1 day on ctrl+right
        case 40: if (e.ctrlKey) $.datepicker._adjustDate(inst, +7, 'D');
            break; // +1 week on ctrl+down
      }
    else if (e.keyCode == 36 && e.ctrlKey) // display the date picker on ctrl+home
      $.datepicker._showDatepicker(this);
  },

  /* Filter entered characters - based on date format. */
  _doKeyPress: function(e) {
    var inst = $.datepicker._getInst(this._calId);
    var chars = $.datepicker._possibleChars(inst._get('dateFormat'));
    var chr = String.fromCharCode(e.charCode == undefined ? e.keyCode : e.charCode);
    return e.ctrlKey || (chr < ' ' || !chars || chars.indexOf(chr) > -1);
  },

  /* Attach the date picker to an input field. */
  _connectDatepicker: function(target, inst) {
    var input = $(target);
    if (input.is('.' + this.markerClassName))
      return;
    var appendText = inst._get('appendText');
    var isRTL = inst._get('isRTL');
    if (appendText) {
      if (isRTL)
        input.before('<span class="datepicker_append">' + appendText);
      else
        input.after('<span class="datepicker_append">' + appendText);
    }
    var showOn = inst._get('showOn');
    if (showOn == 'focus' || showOn == 'both') // pop-up date picker when in the marked field
      input.focus(this._showDatepicker);
    if (showOn == 'button' || showOn == 'both') { // pop-up date picker when button clicked
      input.wrap('<span class="datepicker_wrap">');
      var buttonText = inst._get('buttonText');
      var buttonImage = inst._get('buttonImage');
      var trigger = $(inst._get('buttonImageOnly') ? 
        $('<img>').addClass('datepicker_trigger').attr({ src: buttonImage, alt: buttonText, title: buttonText }) :
        $('<button>').addClass('datepicker_trigger').attr({ type: 'button' }).html(buttonImage != '' ? 
            $('<img>').attr({ src:buttonImage, alt:buttonText, title:buttonText }) : buttonText));
      if (isRTL)
        input.before(trigger);
      else
        input.after(trigger);
      trigger.click(function() {
        if ($.datepicker._datepickerShowing && $.datepicker._lastInput == target)
          $.datepicker._hideDatepicker();
        else
          $.datepicker._showDatepicker(target);
      });
        }
    input.addClass(this.markerClassName).keydown(this._doKeyDown).keypress(this._doKeyPress)
      .bind("setData.datepicker", function(event, key, value) {
        inst._settings[key] = value;
      }).bind("getData.datepicker", function(event, key) {
        return inst._get(key);
      });
    input[0]._calId = inst._id;
  },

  /* Attach an inline date picker to a div. */
  _inlineDatepicker: function(target, inst) {
    var input = $(target);
    if (input.is('.' + this.markerClassName))
      return;
    input.addClass(this.markerClassName).append(inst._datepickerDiv)
      .bind("setData.datepicker", function(event, key, value){
        inst._settings[key] = value;
      }).bind("getData.datepicker", function(event, key){
        return inst._get(key);
      });
    input[0]._calId = inst._id;
    this._updateDatepicker(inst);
  },

  /* Tidy up after displaying the date picker. */
  _inlineShow: function(inst) {
    var numMonths = inst._getNumberOfMonths(); // fix width for dynamic number of date pickers
    inst._datepickerDiv.width(numMonths[1] * $('.datepicker', inst._datepickerDiv[0]).width());
  }, 

  /* Pop-up the date picker in a "dialog" box.
     @param  input     element - ignored
     @param  dateText  string - the initial date to display (in the current format)
     @param  onSelect  function - the function(dateText) to call when a date is selected
     @param  settings  object - update the dialog date picker instance's settings (anonymous object)
     @param  pos       int[2] - coordinates for the dialog's position within the screen or
                       event - with x/y coordinates or
                       leave empty for default (screen centre)
     @return the manager object */
  _dialogDatepicker: function(input, dateText, onSelect, settings, pos) {
    var inst = this._dialogInst; // internal instance
    if (!inst) {
      inst = this._dialogInst = new DatepickerInstance({}, false);
      this._dialogInput = $('<input type="text" size="1" style="position: absolute; top: -100px;"/>');
      this._dialogInput.keydown(this._doKeyDown);
      $('body').append(this._dialogInput);
      this._dialogInput[0]._calId = inst._id;
    }
    extendRemove(inst._settings, settings || {});
    this._dialogInput.val(dateText);

    this._pos = (pos ? (pos.length ? pos : [pos.pageX, pos.pageY]) : null);
    if (!this._pos) {
      var browserWidth = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;
      var browserHeight = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
      var scrollX = document.documentElement.scrollLeft || document.body.scrollLeft;
      var scrollY = document.documentElement.scrollTop || document.body.scrollTop;
      this._pos = // should use actual width/height below
        [(browserWidth / 2) - 100 + scrollX, (browserHeight / 2) - 150 + scrollY];
    }

    // move input on screen for focus, but hidden behind dialog
    this._dialogInput.css('left', this._pos[0] + 'px').css('top', this._pos[1] + 'px');
    inst._settings.onSelect = onSelect;
    this._inDialog = true;
    this._datepickerDiv.addClass('datepicker_dialog');
    this._showDatepicker(this._dialogInput[0]);
    if ($.blockUI)
      $.blockUI(this._datepickerDiv);
    return this;
  },

  /* Pop-up the date picker for a given input field.
     @param  input  element - the input field attached to the date picker or
                    event - if triggered by focus */
  _showDatepicker: function(input) {
    input = input.target || input;
    if (input.nodeName.toLowerCase() != 'input') // find from button/image trigger
      input = $('input', input.parentNode)[0];
    if ($.datepicker._isDisabledDatepicker(input) || $.datepicker._lastInput == input) // already here
      return;
    var inst = $.datepicker._getInst(input._calId);
    var beforeShow = inst._get('beforeShow');
    extendRemove(inst._settings, (beforeShow ? beforeShow.apply(input, [input, inst]) : {}));
    $.datepicker._hideDatepicker(null, '');
    $.datepicker._lastInput = input;
    inst._setDateFromField(input);
    if ($.datepicker._inDialog) // hide cursor
      input.value = '';
    if (!$.datepicker._pos) { // position below input
      $.datepicker._pos = $.datepicker._findPos(input);
      $.datepicker._pos[1] += input.offsetHeight; // add the height
    }
    var isFixed = false;
    $(input).parents().each(function() {
      isFixed |= $(this).css('position') == 'fixed';
    });
    if (isFixed && $.browser.opera) { // correction for Opera when fixed and scrolled
      $.datepicker._pos[0] -= document.documentElement.scrollLeft;
      $.datepicker._pos[1] -= document.documentElement.scrollTop;
    }
    inst._datepickerDiv.css('position', ($.datepicker._inDialog && $.blockUI ?
      'static' : (isFixed ? 'fixed' : 'absolute')))
      .css({ left: $.datepicker._pos[0] + 'px', top: $.datepicker._pos[1] + 'px' });
    $.datepicker._pos = null;
    inst._rangeStart = null;
    $.datepicker._updateDatepicker(inst);
    if (!inst._inline) {
      var speed = inst._get('speed');
      var postProcess = function() {
        $.datepicker._datepickerShowing = true;
        $.datepicker._afterShow(inst);
      };
      var showAnim = inst._get('showAnim') || 'show';
      inst._datepickerDiv[showAnim](speed, postProcess);
      if (speed == '')
        postProcess();
      if (inst._input[0].type != 'hidden')
        inst._input[0].focus();
      $.datepicker._curInst = inst;
    }
  },

  /* Generate the date picker content. */
  _updateDatepicker: function(inst) {
    inst._datepickerDiv.empty().append(inst._generateDatepicker());
    var numMonths = inst._getNumberOfMonths();
    if (numMonths[0] != 1 || numMonths[1] != 1)
      inst._datepickerDiv.addClass('datepicker_multi');
    else
      inst._datepickerDiv.removeClass('datepicker_multi');

    if (inst._get('isRTL'))
      inst._datepickerDiv.addClass('datepicker_rtl');
    else
      inst._datepickerDiv.removeClass('datepicker_rtl');

    if (inst._input && inst._input[0].type != 'hidden')
      $(inst._input[0]).focus();
  },

  /* Tidy up after displaying the date picker. */
  _afterShow: function(inst) {
    var numMonths = inst._getNumberOfMonths(); // fix width for dynamic number of date pickers
    inst._datepickerDiv.width(numMonths[1] * $('.datepicker', inst._datepickerDiv[0])[0].offsetWidth);
    if ($.browser.msie && parseInt($.browser.version) < 7) { // fix IE < 7 select problems
      $('iframe.datepicker_cover').css({width: inst._datepickerDiv.width() + 4,
        height: inst._datepickerDiv.height() + 4});
    }
    // re-position on screen if necessary
    var isFixed = inst._datepickerDiv.css('position') == 'fixed';
    var pos = inst._input ? $.datepicker._findPos(inst._input[0]) : null;
    var browserWidth = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth;
    var browserHeight = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
    var scrollX = (isFixed ? 0 : document.documentElement.scrollLeft || document.body.scrollLeft);
    var scrollY = (isFixed ? 0 : document.documentElement.scrollTop || document.body.scrollTop);
    // reposition date picker horizontally if outside the browser window
    if ((inst._datepickerDiv.offset().left + inst._datepickerDiv.width() -
        (isFixed && $.browser.msie ? document.documentElement.scrollLeft : 0)) >
        (browserWidth + scrollX)) {
      inst._datepickerDiv.css('left', Math.max(scrollX,
        pos[0] + (inst._input ? $(inst._input[0]).width() : null) - inst._datepickerDiv.width() -
        (isFixed && $.browser.opera ? document.documentElement.scrollLeft : 0)) + 'px');
    }
    // reposition date picker vertically if outside the browser window
    if ((inst._datepickerDiv.offset().top + inst._datepickerDiv.height() -
        (isFixed && $.browser.msie ? document.documentElement.scrollTop : 0)) >
        (browserHeight + scrollY) ) {
      inst._datepickerDiv.css('top', Math.max(scrollY,
        pos[1] - (this._inDialog ? 0 : inst._datepickerDiv.height()) -
        (isFixed && $.browser.opera ? document.documentElement.scrollTop : 0)) + 'px');
    }
  },
  
  /* Find an object's position on the screen. */
  _findPos: function(obj) {
        while (obj && (obj.type == 'hidden' || obj.nodeType != 1)) {
            obj = obj.nextSibling;
        }
        var position = $(obj).offset();
      return [position.left, position.top];
  },

  /* Hide the date picker from view.
     @param  input  element - the input field attached to the date picker
     @param  speed  string - the speed at which to close the date picker */
  _hideDatepicker: function(input, speed) {
    var inst = this._curInst;
    if (!inst)
      return;
    var rangeSelect = inst._get('rangeSelect');
    if (rangeSelect && this._stayOpen) {
      this._selectDate(inst, inst._formatDate(
        inst._currentDay, inst._currentMonth, inst._currentYear));
    }
    this._stayOpen = false;
    if (this._datepickerShowing) {
      speed = (speed != null ? speed : inst._get('speed'));
      var showAnim = inst._get('showAnim');
      inst._datepickerDiv[(showAnim == 'slideDown' ? 'slideUp' :
        (showAnim == 'fadeIn' ? 'fadeOut' : 'hide'))](speed, function() {
        $.datepicker._tidyDialog(inst);
      });
      if (speed == '')
        this._tidyDialog(inst);
      var onClose = inst._get('onClose');
      if (onClose) {
        onClose.apply((inst._input ? inst._input[0] : null),
          [inst._getDate(), inst]);  // trigger custom callback
      }
      this._datepickerShowing = false;
      this._lastInput = null;
      inst._settings.prompt = null;
      if (this._inDialog) {
        this._dialogInput.css({ position: 'absolute', left: '0', top: '-100px' });
        if ($.blockUI) {
          $.unblockUI();
          $('body').append(this._datepickerDiv);
        }
      }
      this._inDialog = false;
    }
    this._curInst = null;
  },

  /* Tidy up after a dialog display. */
  _tidyDialog: function(inst) {
    inst._datepickerDiv.removeClass('datepicker_dialog').unbind('.datepicker');
    $('.datepicker_prompt', inst._datepickerDiv).remove();
  },

  /* Close date picker if clicked elsewhere. */
  _checkExternalClick: function(event) {
    if (!$.datepicker._curInst)
      return;
    var $target = $(event.target);
    if (($target.parents("#datepicker_div").length == 0) &&
        ($target.attr('class') != 'datepicker_trigger') &&
        $.datepicker._datepickerShowing && !($.datepicker._inDialog && $.blockUI)) {
      $.datepicker._hideDatepicker(null, '');
    }
  },

  /* Adjust one of the date sub-fields. */
  _adjustDate: function(id, offset, period) {
    var inst = this._getInst(id);
    inst._adjustDate(offset, period);
    this._updateDatepicker(inst);
  },

  /* Action for current link. */
  _gotoToday: function(id) {
    var date = new Date();
    var inst = this._getInst(id);
    inst._selectedDay = date.getDate();
    inst._drawMonth = inst._selectedMonth = date.getMonth();
    inst._drawYear = inst._selectedYear = date.getFullYear();
    this._adjustDate(inst);
  },

  /* Action for selecting a new month/year. */
  _selectMonthYear: function(id, select, period) {
    var inst = this._getInst(id);
    inst._selectingMonthYear = false;
    inst[period == 'M' ? '_drawMonth' : '_drawYear'] =
      select.options[select.selectedIndex].value - 0;
    this._adjustDate(inst);
  },

  /* Restore input focus after not changing month/year. */
  _clickMonthYear: function(id) {
    var inst = this._getInst(id);
    if (inst._input && inst._selectingMonthYear && !$.browser.msie)
      inst._input[0].focus();
    inst._selectingMonthYear = !inst._selectingMonthYear;
  },

  /* Action for changing the first week day. */
  _changeFirstDay: function(id, day) {
    var inst = this._getInst(id);
    inst._settings.firstDay = day;
    this._updateDatepicker(inst);
  },

  /* Action for selecting a day. */
  _selectDay: function(id, month, year, td) {
    if ($(td).is('.datepicker_unselectable'))
      return;
    var inst = this._getInst(id);
    var rangeSelect = inst._get('rangeSelect');
    if (rangeSelect) {
      if (!this._stayOpen) {
        $('.datepicker td').removeClass('datepicker_currentDay');
        $(td).addClass('datepicker_currentDay');
      } 
      this._stayOpen = !this._stayOpen;
    }
    inst._selectedDay = inst._currentDay = $('a', td).html();
    inst._selectedMonth = inst._currentMonth = month;
    inst._selectedYear = inst._currentYear = year;
    this._selectDate(id, inst._formatDate(
      inst._currentDay, inst._currentMonth, inst._currentYear));
    if (this._stayOpen) {
      inst._endDay = inst._endMonth = inst._endYear = null;
      inst._rangeStart = new Date(inst._currentYear, inst._currentMonth, inst._currentDay);
      this._updateDatepicker(inst);
    }
    else if (rangeSelect) {
      inst._endDay = inst._currentDay;
      inst._endMonth = inst._currentMonth;
      inst._endYear = inst._currentYear;
      inst._selectedDay = inst._currentDay = inst._rangeStart.getDate();
      inst._selectedMonth = inst._currentMonth = inst._rangeStart.getMonth();
      inst._selectedYear = inst._currentYear = inst._rangeStart.getFullYear();
      inst._rangeStart = null;
      if (inst._inline)
        this._updateDatepicker(inst);
    }
  },

  /* Erase the input field and hide the date picker. */
  _clearDate: function(id) {
    var inst = this._getInst(id);
    if (inst._get('mandatory'))
      return;
    this._stayOpen = false;
    inst._endDay = inst._endMonth = inst._endYear = inst._rangeStart = null;
    this._selectDate(inst, '');
  },

  /* Update the input field with the selected date. */
  _selectDate: function(id, dateStr) {
    var inst = this._getInst(id);
    dateStr = (dateStr != null ? dateStr : inst._formatDate());
    if (inst._rangeStart)
      dateStr = inst._formatDate(inst._rangeStart) + inst._get('rangeSeparator') + dateStr;
    if (inst._input)
      inst._input.val(dateStr);
    var onSelect = inst._get('onSelect');
    if (onSelect)
      onSelect.apply((inst._input ? inst._input[0] : null), [dateStr, inst]);  // trigger custom callback
    else if (inst._input)
      inst._input.trigger('change'); // fire the change event
    if (inst._inline)
      this._updateDatepicker(inst);
    else if (!this._stayOpen) {
      this._hideDatepicker(null, inst._get('speed'));
      this._lastInput = inst._input[0];
      if (typeof(inst._input[0]) != 'object')
        inst._input[0].focus(); // restore focus
      this._lastInput = null;
    }
  },

  /* Set as beforeShowDay function to prevent selection of weekends.
     @param  date  Date - the date to customise
     @return [boolean, string] - is this date selectable?, what is its CSS class? */
  noWeekends: function(date) {
    var day = date.getDay();
    return [(day > 0 && day < 6), ''];
  },
  
  /* Set as calculateWeek to determine the week of the year based on the ISO 8601 definition.
     @param  date  Date - the date to get the week for
     @return  number - the number of the week within the year that contains this date */
  iso8601Week: function(date) {
    var checkDate = new Date(date.getFullYear(), date.getMonth(), date.getDate(), (date.getTimezoneOffset() / -60));
    var firstMon = new Date(checkDate.getFullYear(), 1 - 1, 4); // First week always contains 4 Jan
    var firstDay = firstMon.getDay() || 7; // Day of week: Mon = 1, ..., Sun = 7
    firstMon.setDate(firstMon.getDate() + 1 - firstDay); // Preceding Monday
    if (firstDay < 4 && checkDate < firstMon) { // Adjust first three days in year if necessary
      checkDate.setDate(checkDate.getDate() - 3); // Generate for previous year
      return $.datepicker.iso8601Week(checkDate);
    } else if (checkDate > new Date(checkDate.getFullYear(), 12 - 1, 28)) { // Check last three days in year
      firstDay = new Date(checkDate.getFullYear() + 1, 1 - 1, 4).getDay() || 7;
      if (firstDay > 4 && (checkDate.getDay() || 7) < firstDay - 3) { // Adjust if necessary
        checkDate.setDate(checkDate.getDate() + 3); // Generate for next year
        return $.datepicker.iso8601Week(checkDate);
      }
    }
    return Math.floor(((checkDate - firstMon) / 86400000) / 7) + 1; // Weeks to given date
  },
  
  /* Provide status text for a particular date.
     @param  date  the date to get the status for
     @param  inst  the current datepicker instance
     @return  the status display text for this date */
  dateStatus: function(date, inst) {
    return $.datepicker.formatDate(inst._get('dateStatus'), date, inst._getFormatConfig());
  },

  /* Parse a string value into a date object.
     The format can be combinations of the following:
     d  - day of month (no leading zero)
     dd - day of month (two digit)
     D  - day name short
     DD - day name long
     m  - month of year (no leading zero)
     mm - month of year (two digit)
     M  - month name short
     MM - month name long
     y  - year (two digit)
     yy - year (four digit)
     '...' - literal text
     '' - single quote

     @param  format           String - the expected format of the date
     @param  value            String - the date in the above format
     @param  settings  Object - attributes include:
                       shortYearCutoff  Number - the cutoff year for determining the century (optional)
                       dayNamesShort    String[7] - abbreviated names of the days from Sunday (optional)
                       dayNames         String[7] - names of the days from Sunday (optional)
                       monthNamesShort  String[12] - abbreviated names of the months (optional)
                       monthNames       String[12] - names of the months (optional)
     @return  Date - the extracted date value or null if value is blank */
  parseDate: function (format, value, settings) {
    if (format == null || value == null)
      throw 'Invalid arguments';
    value = (typeof value == 'object' ? value.toString() : value + '');
    if (value == '')
      return null;
    var shortYearCutoff = (settings ? settings.shortYearCutoff : null) || this._defaults.shortYearCutoff;
    var dayNamesShort = (settings ? settings.dayNamesShort : null) || this._defaults.dayNamesShort;
    var dayNames = (settings ? settings.dayNames : null) || this._defaults.dayNames;
    var monthNamesShort = (settings ? settings.monthNamesShort : null) || this._defaults.monthNamesShort;
    var monthNames = (settings ? settings.monthNames : null) || this._defaults.monthNames;
    var year = -1;
    var month = -1;
    var day = -1;
    var literal = false;
    // Check whether a format character is doubled
    var lookAhead = function(match) {
      var matches = (iFormat + 1 < format.length && format.charAt(iFormat + 1) == match);
      if (matches)
        iFormat++;
      return matches; 
    };
    // Extract a number from the string value
    var getNumber = function(match) {
      lookAhead(match);
      var size = (match == 'y' ? 4 : 2);
      var num = 0;
      while (size > 0 && iValue < value.length &&
          value.charAt(iValue) >= '0' && value.charAt(iValue) <= '9') {
        num = num * 10 + (value.charAt(iValue++) - 0);
        size--;
      }
      if (size == (match == 'y' ? 4 : 2))
        throw 'Missing number at position ' + iValue;
      return num;
    };
    // Extract a name from the string value and convert to an index
    var getName = function(match, shortNames, longNames) {
      var names = (lookAhead(match) ? longNames : shortNames);
      var size = 0;
      for (var j = 0; j < names.length; j++)
        size = Math.max(size, names[j].length);
      var name = '';
      var iInit = iValue;
      while (size > 0 && iValue < value.length) {
        name += value.charAt(iValue++);
        for (var i = 0; i < names.length; i++)
          if (name == names[i])
            return i + 1;
        size--;
      }
      throw 'Unknown name at position ' + iInit;
    };
    // Confirm that a literal character matches the string value
    var checkLiteral = function() {
      if (value.charAt(iValue) != format.charAt(iFormat))
        throw 'Unexpected literal at position ' + iValue;
      iValue++;
    };
    var iValue = 0;
    for (var iFormat = 0; iFormat < format.length; iFormat++) {
      if (literal)
        if (format.charAt(iFormat) == "'" && !lookAhead("'"))
          literal = false;
        else
          checkLiteral();
      else
        switch (format.charAt(iFormat)) {
          case 'd':
            day = getNumber('d');
            break;
          case 'D': 
            getName('D', dayNamesShort, dayNames);
            break;
          case 'm': 
            month = getNumber('m');
            break;
          case 'M':
            month = getName('M', monthNamesShort, monthNames); 
            break;
          case 'y':
            year = getNumber('y');
            break;
          case "'":
            if (lookAhead("'"))
              checkLiteral();
            else
              literal = true;
            break;
          default:
            checkLiteral();
        }
    }
    if (year < 100) {
      year += new Date().getFullYear() - new Date().getFullYear() % 100 +
        (year <= shortYearCutoff ? 0 : -100);
    }
    var date = new Date(year, month - 1, day);
    if (date.getFullYear() != year || date.getMonth() + 1 != month || date.getDate() != day) {
      throw 'Invalid date'; // E.g. 31/02/*
    }
    return date;
  },

  /* Format a date object into a string value.
     The format can be combinations of the following:
     d  - day of month (no leading zero)
     dd - day of month (two digit)
     D  - day name short
     DD - day name long
     m  - month of year (no leading zero)
     mm - month of year (two digit)
     M  - month name short
     MM - month name long
     y  - year (two digit)
     yy - year (four digit)
     '...' - literal text
     '' - single quote

     @param  format    String - the desired format of the date
     @param  date      Date - the date value to format
     @param  settings  Object - attributes include:
                       dayNamesShort    String[7] - abbreviated names of the days from Sunday (optional)
                       dayNames         String[7] - names of the days from Sunday (optional)
                       monthNamesShort  String[12] - abbreviated names of the months (optional)
                       monthNames       String[12] - names of the months (optional)
     @return  String - the date in the above format */
  formatDate: function (format, date, settings) {
    if (!date)
      return '';
    var dayNamesShort = (settings ? settings.dayNamesShort : null) || this._defaults.dayNamesShort;
    var dayNames = (settings ? settings.dayNames : null) || this._defaults.dayNames;
    var monthNamesShort = (settings ? settings.monthNamesShort : null) || this._defaults.monthNamesShort;
    var monthNames = (settings ? settings.monthNames : null) || this._defaults.monthNames;
    // Check whether a format character is doubled
    var lookAhead = function(match) {
      var matches = (iFormat + 1 < format.length && format.charAt(iFormat + 1) == match);
      if (matches)
        iFormat++;
      return matches; 
    };
    // Format a number, with leading zero if necessary
    var formatNumber = function(match, value) {
      return (lookAhead(match) && value < 10 ? '0' : '') + value;
    };
    // Format a name, short or long as requested
    var formatName = function(match, value, shortNames, longNames) {
      return (lookAhead(match) ? longNames[value] : shortNames[value]);
    };
    var output = '';
    var literal = false;
    if (date) {
      for (var iFormat = 0; iFormat < format.length; iFormat++) {
        if (literal)
          if (format.charAt(iFormat) == "'" && !lookAhead("'"))
            literal = false;
          else
            output += format.charAt(iFormat);
        else
          switch (format.charAt(iFormat)) {
            case 'd':
              output += formatNumber('d', date.getDate()); 
              break;
            case 'D': 
              output += formatName('D', date.getDay(), dayNamesShort, dayNames);
              break;
            case 'm': 
              output += formatNumber('m', date.getMonth() + 1); 
              break;
            case 'M':
              output += formatName('M', date.getMonth(), monthNamesShort, monthNames); 
              break;
            case 'y':
              output += (lookAhead('y') ? date.getFullYear() : 
                (date.getYear() % 100 < 10 ? '0' : '') + date.getYear() % 100);
              break;
            case "'":
              if (lookAhead("'"))
                output += "'";
              else
                literal = true;
              break;
            default:
              output += format.charAt(iFormat);
          }
      }
    }
    return output;
  },

  /* Extract all possible characters from the date format. */
  _possibleChars: function (format) {
    var chars = '';
    var literal = false;
    for (var iFormat = 0; iFormat < format.length; iFormat++)
      if (literal)
        if (format.charAt(iFormat) == "'" && !lookAhead("'"))
          literal = false;
        else
          chars += format.charAt(iFormat);
      else
        switch (format.charAt(iFormat)) {
          case 'd' || 'm' || 'y':
            chars += '0123456789'; 
            break;
          case 'D' || 'M':
            return null; // Accept anything
          case "'":
            if (lookAhead("'"))
              chars += "'";
            else
              literal = true;
            break;
          default:
            chars += format.charAt(iFormat);
        }
    return chars;
  }
});

/* Individualised settings for date picker functionality applied to one or more related inputs.
   Instances are managed and manipulated through the Datepicker manager. */
function DatepickerInstance(settings, inline) {
  this._id = $.datepicker._register(this);
  this._selectedDay = 0; // Current date for selection
  this._selectedMonth = 0; // 0-11
  this._selectedYear = 0; // 4-digit year
  this._drawMonth = 0; // Current month at start of datepicker
  this._drawYear = 0;
  this._input = null; // The attached input field
  this._inline = inline; // True if showing inline, false if used in a popup
  this._datepickerDiv = (!inline ? $.datepicker._datepickerDiv :
    $('<div id="datepicker_div_' + this._id + '" class="datepicker_inline">'));
  // customise the date picker object - uses manager defaults if not overridden
  this._settings = extendRemove(settings || {}); // clone
  if (inline)
    this._setDate(this._getDefaultDate());
}

$.extend(DatepickerInstance.prototype, {
  /* Get a setting value, defaulting if necessary. */
  _get: function(name) {
    return this._settings[name] !== undefined ? this._settings[name] : $.datepicker._defaults[name];
  },

  /* Parse existing date and initialise date picker. */
  _setDateFromField: function(input) {
    this._input = $(input);
    var dateFormat = this._get('dateFormat');
    var dates = this._input ? this._input.val().split(this._get('rangeSeparator')) : null; 
    this._endDay = this._endMonth = this._endYear = null;
    var date = defaultDate = this._getDefaultDate();
    if (dates.length > 0) {
      var settings = this._getFormatConfig();
      if (dates.length > 1) {
        date = $.datepicker.parseDate(dateFormat, dates[1], settings) || defaultDate;
        this._endDay = date.getDate();
        this._endMonth = date.getMonth();
        this._endYear = date.getFullYear();
      }
      try {
        date = $.datepicker.parseDate(dateFormat, dates[0], settings) || defaultDate;
      } catch (e) {
        $.datepicker.log(e);
        date = defaultDate;
      }
    }
    this._selectedDay = date.getDate();
    this._drawMonth = this._selectedMonth = date.getMonth();
    this._drawYear = this._selectedYear = date.getFullYear();
    this._currentDay = (dates[0] ? date.getDate() : 0);
    this._currentMonth = (dates[0] ? date.getMonth() : 0);
    this._currentYear = (dates[0] ? date.getFullYear() : 0);
    this._adjustDate();
  },
  
  /* Retrieve the default date shown on opening. */
  _getDefaultDate: function() {
    var date = this._determineDate('defaultDate', new Date());
    var minDate = this._getMinMaxDate('min', true);
    var maxDate = this._getMinMaxDate('max');
    date = (minDate && date < minDate ? minDate : date);
    date = (maxDate && date > maxDate ? maxDate : date);
    return date;
  },

  /* A date may be specified as an exact value or a relative one. */
  _determineDate: function(name, defaultDate) {
    var offsetNumeric = function(offset) {
      var date = new Date();
      date.setDate(date.getDate() + offset);
      return date;
    };
    var offsetString = function(offset, getDaysInMonth) {
      var date = new Date();
      var matches = /^([+-]?[0-9]+)\s*(d|D|w|W|m|M|y|Y)?$/.exec(offset);
      if (matches) {
        var year = date.getFullYear();
        var month = date.getMonth();
        var day = date.getDate();
        switch (matches[2] || 'd') {
          case 'd' : case 'D' :
            day += (matches[1] - 0); break;
          case 'w' : case 'W' :
            day += (matches[1] * 7); break;
          case 'm' : case 'M' :
            month += (matches[1] - 0); 
            day = Math.min(day, getDaysInMonth(year, month));
            break;
          case 'y': case 'Y' :
            year += (matches[1] - 0);
            day = Math.min(day, getDaysInMonth(year, month));
            break;
        }
        date = new Date(year, month, day);
      }
      return date;
    };
    var date = this._get(name);
    return (date == null ? defaultDate :
      (typeof date == 'string' ? offsetString(date, this._getDaysInMonth) :
      (typeof date == 'number' ? offsetNumeric(date) : date)));
  },

  /* Set the date(s) directly. */
  _setDate: function(date, endDate) {
    this._selectedDay = this._currentDay = date.getDate();
    this._drawMonth = this._selectedMonth = this._currentMonth = date.getMonth();
    this._drawYear = this._selectedYear = this._currentYear = date.getFullYear();
    if (this._get('rangeSelect')) {
      if (endDate) {
        this._endDay = endDate.getDate();
        this._endMonth = endDate.getMonth();
        this._endYear = endDate.getFullYear();
      } else {
        this._endDay = this._currentDay;
        this._endMonth = this._currentMonth;
        this._endYear = this._currentYear;
      }
    }
    this._adjustDate();
  },

  /* Retrieve the date(s) directly. */
  _getDate: function() {
    var startDate = (!this._currentYear || (this._input && this._input.val() == '') ? null :
      new Date(this._currentYear, this._currentMonth, this._currentDay));
    if (this._get('rangeSelect')) {
      return [startDate, (!this._endYear ? null :
        new Date(this._endYear, this._endMonth, this._endDay))];
    } else
      return startDate;
  },

  /* Generate the HTML for the current state of the date picker. */
  _generateDatepicker: function() {
    var today = new Date();
    today = new Date(today.getFullYear(), today.getMonth(), today.getDate()); // clear time
    var showStatus = this._get('showStatus');
    var isRTL = this._get('isRTL');
    // build the date picker HTML
    var clear = (this._get('mandatory') ? '' :
      '<div class="datepicker_clear"><a onclick="jQuery.datepicker._clearDate(' + this._id + ');"' + 
      (showStatus ? this._addStatus(this._get('clearStatus') || '&#xa0;') : '') + '>' +
      this._get('clearText') + '</a></div>');
    var controls = '<div class="datepicker_control">' + (isRTL ? '' : clear) +
      '<div class="datepicker_close"><a onclick="jQuery.datepicker._hideDatepicker();"' +
      (showStatus ? this._addStatus(this._get('closeStatus') || '&#xa0;') : '') + '>' +
      this._get('closeText') + '</a></div>' + (isRTL ? clear : '')  + '</div>';
    var prompt = this._get('prompt');
    var closeAtTop = this._get('closeAtTop');
    var hideIfNoPrevNext = this._get('hideIfNoPrevNext');
    var numMonths = this._getNumberOfMonths();
    var stepMonths = this._get('stepMonths');
    var isMultiMonth = (numMonths[0] != 1 || numMonths[1] != 1);
    var minDate = this._getMinMaxDate('min', true);
    var maxDate = this._getMinMaxDate('max');
    var drawMonth = this._drawMonth;
    var drawYear = this._drawYear;
    if (maxDate) {
      var maxDraw = new Date(maxDate.getFullYear(),
        maxDate.getMonth() - numMonths[1] + 1, maxDate.getDate());
      maxDraw = (minDate && maxDraw < minDate ? minDate : maxDraw);
      while (new Date(drawYear, drawMonth, 1) > maxDraw) {
        drawMonth--;
        if (drawMonth < 0) {
          drawMonth = 11;
          drawYear--;
        }
      }
    }
    // controls and links
    var prev = '<div class="datepicker_prev">' + (this._canAdjustMonth(-1, drawYear, drawMonth) ? 
      '<a onclick="jQuery.datepicker._adjustDate(' + this._id + ', -' + stepMonths + ', \'M\');"' +
      (showStatus ? this._addStatus(this._get('prevStatus') || '&#xa0;') : '') + '>' +
      this._get('prevText') + '</a>' :
      (hideIfNoPrevNext ? '' : '<label>' + this._get('prevText') + '</label>')) + '</div>';
    var next = '<div class="datepicker_next">' + (this._canAdjustMonth(+1, drawYear, drawMonth) ?
      '<a onclick="jQuery.datepicker._adjustDate(' + this._id + ', +' + stepMonths + ', \'M\');"' +
      (showStatus ? this._addStatus(this._get('nextStatus') || '&#xa0;') : '') + '>' +
      this._get('nextText') + '</a>' :
      (hideIfNoPrevNext ? '>' : '<label>' + this._get('nextText') + '</label>')) + '</div>';
    var html = (prompt ? '<div class="datepicker_prompt">' + prompt + '</div>' : '') +
      (closeAtTop && !this._inline ? controls : '') +
      '<div class="datepicker_links">' + (isRTL ? next : prev) +
      (this._isInRange(today) ? '<div class="datepicker_current">' +
      '<a onclick="jQuery.datepicker._gotoToday(' + this._id + ');"' +
      (showStatus ? this._addStatus(this._get('currentStatus') || '&#xa0;') : '') + '>' +
      this._get('currentText') + '</a></div>' : '') + (isRTL ? prev : next) + '</div>';
    var showWeeks = this._get('showWeeks');
    for (var row = 0; row < numMonths[0]; row++)
      for (var col = 0; col < numMonths[1]; col++) {
        var selectedDate = new Date(drawYear, drawMonth, this._selectedDay);
        html += '<div class="datepicker_oneMonth' + (col == 0 ? ' datepicker_newRow' : '') + '">' +
          this._generateMonthYearHeader(drawMonth, drawYear, minDate, maxDate,
          selectedDate, row > 0 || col > 0) + // draw month headers
          '<table class="datepicker" cellpadding="0" cellspacing="0"><thead>' + 
          '<tr class="datepicker_titleRow">' +
          (showWeeks ? '<td>' + this._get('weekHeader') + '</td>' : '');
        var firstDay = this._get('firstDay');
        var changeFirstDay = this._get('changeFirstDay');
        var dayNames = this._get('dayNames');
        var dayNamesShort = this._get('dayNamesShort');
        var dayNamesMin = this._get('dayNamesMin');
        for (var dow = 0; dow < 7; dow++) { // days of the week
          var day = (dow + firstDay) % 7;
          var status = this._get('dayStatus') || '&#xa0;';
          status = (status.indexOf('DD') > -1 ? status.replace(/DD/, dayNames[day]) :
            status.replace(/D/, dayNamesShort[day]));
          html += '<td' + ((dow + firstDay + 6) % 7 >= 5 ? ' class="datepicker_weekEndCell"' : '') + '>' +
            (!changeFirstDay ? '<span' :
            '<a onclick="jQuery.datepicker._changeFirstDay(' + this._id + ', ' + day + ');"') + 
            (showStatus ? this._addStatus(status) : '') + ' title="' + dayNames[day] + '">' +
            dayNamesMin[day] + (changeFirstDay ? '</a>' : '</span>') + '</td>';
        }
        html += '</tr></thead><tbody>';
        var daysInMonth = this._getDaysInMonth(drawYear, drawMonth);
        if (drawYear == this._selectedYear && drawMonth == this._selectedMonth) {
          this._selectedDay = Math.min(this._selectedDay, daysInMonth);
        }
        var leadDays = (this._getFirstDayOfMonth(drawYear, drawMonth) - firstDay + 7) % 7;
        var currentDate = (!this._currentDay ? new Date(9999, 9, 9) :
          new Date(this._currentYear, this._currentMonth, this._currentDay));
        var endDate = this._endDay ? new Date(this._endYear, this._endMonth, this._endDay) : currentDate;
        var printDate = new Date(drawYear, drawMonth, 1 - leadDays);
        var numRows = (isMultiMonth ? 6 : Math.ceil((leadDays + daysInMonth) / 7)); // calculate the number of rows to generate
        var beforeShowDay = this._get('beforeShowDay');
        var showOtherMonths = this._get('showOtherMonths');
        var calculateWeek = this._get('calculateWeek') || $.datepicker.iso8601Week;
        var dateStatus = this._get('statusForDate') || $.datepicker.dateStatus;
        for (var dRow = 0; dRow < numRows; dRow++) { // create date picker rows
          html += '<tr class="datepicker_daysRow">' +
            (showWeeks ? '<td class="datepicker_weekCol">' + calculateWeek(printDate) + '</td>' : '');
          for (var dow = 0; dow < 7; dow++) { // create date picker days
            var daySettings = (beforeShowDay ?
              beforeShowDay.apply((this._input ? this._input[0] : null), [printDate]) : [true, '']);
            var otherMonth = (printDate.getMonth() != drawMonth);
            var unselectable = otherMonth || !daySettings[0] ||
              (minDate && printDate < minDate) || (maxDate && printDate > maxDate);
            html += '<td class="datepicker_daysCell' +
              ((dow + firstDay + 6) % 7 >= 5 ? ' datepicker_weekEndCell' : '') + // highlight weekends
              (otherMonth ? ' datepicker_otherMonth' : '') + // highlight days from other months
              (printDate.getTime() == selectedDate.getTime() && drawMonth == this._selectedMonth ?
              ' datepicker_daysCellOver' : '') + // highlight selected day
              (unselectable ? ' datepicker_unselectable' : '') +  // highlight unselectable days
              (otherMonth && !showOtherMonths ? '' : ' ' + daySettings[1] + // highlight custom dates
              (printDate.getTime() >= currentDate.getTime() && printDate.getTime() <= endDate.getTime() ?  // in current range
              ' datepicker_currentDay' : '') + // highlight selected day
              (printDate.getTime() == today.getTime() ? ' datepicker_today' : '')) + '"' + // highlight today (if different)
              (unselectable ? '' : ' onmouseover="jQuery(this).addClass(\'datepicker_daysCellOver\');' +
              (!showStatus || (otherMonth && !showOtherMonths) ? '' : 'jQuery(\'#datepicker_status_' +
              this._id + '\').html(\'' + (dateStatus.apply((this._input ? this._input[0] : null),
              [printDate, this]) || '&#xa0;') +'\');') + '"' +
              ' onmouseout="jQuery(this).removeClass(\'datepicker_daysCellOver\');' +
              (!showStatus || (otherMonth && !showOtherMonths) ? '' : 'jQuery(\'#datepicker_status_' +
              this._id + '\').html(\'&#xa0;\');') + '" onclick="jQuery.datepicker._selectDay(' +
              this._id + ',' + drawMonth + ',' + drawYear + ', this);"') + '>' + // actions
              (otherMonth ? (showOtherMonths ? printDate.getDate() : '&#xa0;') : // display for other months
              (unselectable ? printDate.getDate() : '<a>' + printDate.getDate() + '</a>')) + '</td>'; // display for this month
            printDate.setDate(printDate.getDate() + 1);
          }
          html += '</tr>';
        }
        drawMonth++;
        if (drawMonth > 11) {
          drawMonth = 0;
          drawYear++;
        }
        html += '</tbody></table></div>';
      }
    html += (showStatus ? '<div style="clear: both;"></div><div id="datepicker_status_' + this._id + 
      '" class="datepicker_status">' + (this._get('initStatus') || '&#xa0;') + '</div>' : '') +
      (!closeAtTop && !this._inline ? controls : '') +
      '<div style="clear: both;"></div>' + 
      ($.browser.msie && parseInt($.browser.version) < 7 && !this._inline ? 
      '<iframe src="javascript:false;" class="datepicker_cover"></iframe>' : '');
    return html;
  },
  
  /* Generate the month and year header. */
  _generateMonthYearHeader: function(drawMonth, drawYear, minDate, maxDate, selectedDate, secondary) {
    minDate = (this._rangeStart && minDate && selectedDate < minDate ? selectedDate : minDate);
    var showStatus = this._get('showStatus');
    var html = '<div class="datepicker_header">';
    // month selection
    var monthNames = this._get('monthNames');
    if (secondary || !this._get('changeMonth'))
      html += monthNames[drawMonth] + '&#xa0;';
      
    else {
      var inMinYear = (minDate && minDate.getFullYear() == drawYear);
      var inMaxYear = (maxDate && maxDate.getFullYear() == drawYear);
      html += '<select class="datepicker_newMonth" ' +
        'onchange="jQuery.datepicker._selectMonthYear(' + this._id + ', this, \'M\');" ' +
        'onclick="jQuery.datepicker._clickMonthYear(' + this._id + ');"' +
        (showStatus ? this._addStatus(this._get('monthStatus') || '&#xa0;') : '') + '>';
      for (var month = 0; month < 12; month++) {
        if ((!inMinYear || month >= minDate.getMonth()) &&
            (!inMaxYear || month <= maxDate.getMonth())) {
          html += '<option value="' + month + '"' +
            (month == drawMonth ? ' selected="selected"' : '') +
            '>' + monthNames[month] + '</option>';
        }
      }
      html += '</select>';
    }
    // year selection
    if (secondary || !this._get('changeYear'))
      html += drawYear;
    else {
      // determine range of years to display
      var years = this._get('yearRange').split(':');
      var year = 0;
      var endYear = 0;
      if (years.length != 2) {
        year = drawYear - 10;
        endYear = drawYear + 10;
      } else if (years[0].charAt(0) == '+' || years[0].charAt(0) == '-') {
        year = drawYear + parseInt(years[0], 10);
        endYear = drawYear + parseInt(years[1], 10);
      } else {
        year = parseInt(years[0], 10);
        endYear = parseInt(years[1], 10);
      }
      year = (minDate ? Math.max(year, minDate.getFullYear()) : year);
      endYear = (maxDate ? Math.min(endYear, maxDate.getFullYear()) : endYear);
      html += '<select class="datepicker_newYear" ' +
        'onchange="jQuery.datepicker._selectMonthYear(' + this._id + ', this, \'Y\');" ' +
        'onclick="jQuery.datepicker._clickMonthYear(' + this._id + ');"' +
        (showStatus ? this._addStatus(this._get('yearStatus') || '&#xa0;') : '') + '>';
      for (; year <= endYear; year++) {
        html += '<option value="' + year + '"' +
          (year == drawYear ? ' selected="selected"' : '') +
          '>' + year + '</option>';
      }
      html += '</select>';
    }
    html += '</div>'; // Close datepicker_header
    return html;
  },

  /* Provide code to set and clear the status panel. */
  _addStatus: function(text) {
    return ' onmouseover="jQuery(\'#datepicker_status_' + this._id + '\').html(\'' + text + '\');" ' +
      'onmouseout="jQuery(\'#datepicker_status_' + this._id + '\').html(\'&#xa0;\');"';
  },

  /* Adjust one of the date sub-fields. */
  _adjustDate: function(offset, period) {
    var year = this._drawYear + (period == 'Y' ? offset : 0);
    var month = this._drawMonth + (period == 'M' ? offset : 0);
    var day = Math.min(this._selectedDay, this._getDaysInMonth(year, month)) +
      (period == 'D' ? offset : 0);
    var date = new Date(year, month, day);
    // ensure it is within the bounds set
    var minDate = this._getMinMaxDate('min', true);
    var maxDate = this._getMinMaxDate('max');
    date = (minDate && date < minDate ? minDate : date);
    date = (maxDate && date > maxDate ? maxDate : date);
    this._selectedDay = date.getDate();
    this._drawMonth = this._selectedMonth = date.getMonth();
    this._drawYear = this._selectedYear = date.getFullYear();
  },
  
  /* Determine the number of months to show. */
  _getNumberOfMonths: function() {
    var numMonths = this._get('numberOfMonths');
    return (numMonths == null ? [1, 1] : (typeof numMonths == 'number' ? [1, numMonths] : numMonths));
  },

  /* Determine the current maximum date - ensure no time components are set - may be overridden for a range. */
  _getMinMaxDate: function(minMax, checkRange) {
    var date = this._determineDate(minMax + 'Date', null);
    if (date) {
      date.setHours(0);
      date.setMinutes(0);
      date.setSeconds(0);
      date.setMilliseconds(0);
    }
    return date || (checkRange ? this._rangeStart : null);
  },

  /* Find the number of days in a given month. */
  _getDaysInMonth: function(year, month) {
    return 32 - new Date(year, month, 32).getDate();
  },

  /* Find the day of the week of the first of a month. */
  _getFirstDayOfMonth: function(year, month) {
    return new Date(year, month, 1).getDay();
  },

  /* Determines if we should allow a "next/prev" month display change. */
  _canAdjustMonth: function(offset, curYear, curMonth) {
    var numMonths = this._getNumberOfMonths();
    var date = new Date(curYear, curMonth + (offset < 0 ? offset : numMonths[1]), 1);
    if (offset < 0)
      date.setDate(this._getDaysInMonth(date.getFullYear(), date.getMonth()));
    return this._isInRange(date);
  },

  /* Is the given date in the accepted range? */
  _isInRange: function(date) {
    // during range selection, use minimum of selected date and range start
    var newMinDate = (!this._rangeStart ? null :
      new Date(this._selectedYear, this._selectedMonth, this._selectedDay));
    newMinDate = (newMinDate && this._rangeStart < newMinDate ? this._rangeStart : newMinDate);
    var minDate = newMinDate || this._getMinMaxDate('min');
    var maxDate = this._getMinMaxDate('max');
    return ((!minDate || date >= minDate) && (!maxDate || date <= maxDate));
  },
  
  /* Provide the configuration settings for formatting/parsing. */
  _getFormatConfig: function() {
    var shortYearCutoff = this._get('shortYearCutoff');
    shortYearCutoff = (typeof shortYearCutoff != 'string' ? shortYearCutoff :
      new Date().getFullYear() % 100 + parseInt(shortYearCutoff, 10));
    return {shortYearCutoff: shortYearCutoff,
      dayNamesShort: this._get('dayNamesShort'), dayNames: this._get('dayNames'),
      monthNamesShort: this._get('monthNamesShort'), monthNames: this._get('monthNames')};
  },

  /* Format the given date for display. */
  _formatDate: function(day, month, year) {
    if (!day) {
      this._currentDay = this._selectedDay;
      this._currentMonth = this._selectedMonth;
      this._currentYear = this._selectedYear;
    }
    var date = (day ? (typeof day == 'object' ? day : new Date(year, month, day)) :
      new Date(this._currentYear, this._currentMonth, this._currentDay));
    return $.datepicker.formatDate(this._get('dateFormat'), date, this._getFormatConfig());
  }
});

/* jQuery extend now ignores nulls! */
function extendRemove(target, props) {
  $.extend(target, props);
  for (var name in props)
    if (props[name] == null)
      target[name] = null;
  return target;
};

/* Invoke the datepicker functionality.
   @param  options  String - a command, optionally followed by additional parameters or
                    Object - settings for attaching new datepicker functionality
   @return  jQuery object */
$.fn.datepicker = function(options){
  var otherArgs = Array.prototype.slice.call(arguments, 1);
  if (typeof options == 'string' && (options == 'isDisabled' || options == 'getDate')) {
    return $.datepicker['_' + options + 'Datepicker'].apply($.datepicker, [this[0]].concat(otherArgs));
  }
  return this.each(function() {
    typeof options == 'string' ?
      $.datepicker['_' + options + 'Datepicker'].apply($.datepicker, [this].concat(otherArgs)) :
      $.datepicker._attachDatepicker(this, options);
  });
};

$.datepicker = new Datepicker(); // singleton instance
  
/* Initialise the date picker. */
$(document).ready(function() {
  $(document.body).append($.datepicker._datepickerDiv)
    .mousedown($.datepicker._checkExternalClick);
});

})(jQuery);