// Popup Calendar Control
// Taken from https://engineering.purdue.edu/ECN/Support/KnowledgeBase/Docs/20040414131404 //

function positionInfo( object ) 
{
	var p_elm = object;
  	this.getElementLeft = getElementLeft;
  	function getElementLeft() 
	{
    	var x = 0;
    	var elm;
    	if( typeof(p_elm) == "object" )
      		elm = p_elm; 
		else 
      		elm = document.getElementById(p_elm);
			
    	while (elm != null) 
		{
      		x+= elm.offsetLeft;
      		elm = elm.offsetParent;
    	}
    	return parseInt(x);
  	}

  	this.getElementWidth = getElementWidth;
 	function getElementWidth()
	{
    	var elm;
    	if(typeof(p_elm) == "object")
      		elm = p_elm; 
		else 
      		elm = document.getElementById(p_elm);
    	return parseInt(elm.offsetWidth);
  	}

  	this.getElementRight = getElementRight;
  	function getElementRight()
	{
    	return getElementLeft(p_elm) + getElementWidth(p_elm);
  	}

  	this.getElementTop = getElementTop;
  	function getElementTop() 
	{
    	var y = 0;
    	var elm;
    	if(typeof(p_elm) == "object")
      		elm = p_elm; 
		else 
      		elm = document.getElementById(p_elm);
    	while (elm != null) 
		{
      		y+= elm.offsetTop;
      		elm = elm.offsetParent;
    	}
    	return parseInt(y);
  	}

  	this.getElementHeight = getElementHeight;
  	function getElementHeight()
	{
    	var elm;
    	if(typeof(p_elm) == "object")
      		elm = p_elm; 
		else 
      		elm = document.getElementById(p_elm);
    	return parseInt(elm.offsetHeight);
  	}

  	this.getElementBottom = getElementBottom;
  	function getElementBottom()
	{
    	return getElementTop(p_elm) + getElementHeight(p_elm);
  	}
}


function CalendarControl() 
{
	var calendarId = 'CalendarControl';
  	var currentYear = 0;
  	var currentMonth = 0;
  	var currentDay = 0;
  	var selectedYear = 0;
  	var selectedMonth = 0;
  	var selectedDay = 0;

  	var months = ['January','February','March','April','May','June','July','August','September','October','November','December'];
  	var dateField = null;

  	function getProperty(p_property)
	{
    	var p_elm = calendarId;
    	var elm = null;
		
    	if(typeof(p_elm) == "object")
      		elm = p_elm; 
		else 
      		elm = document.getElementById(p_elm);
			
   		if (elm != null)
		{
      		if(elm.style)
			{
        		elm = elm.style;
       			if(elm[p_property])
          			return elm[p_property]; 
				else 
          			return null;
      		} 
			else 
			{
       			 return null;
      		}
    	}
  	}

  	function setElementProperty(p_property, p_value, p_elmId)
	{
    	var p_elm = p_elmId;
    	var elm = null;

    	if(typeof(p_elm) == "object")
      		elm = p_elm;
		else 
      		elm = document.getElementById(p_elm);
			
    	if((elm != null) && (elm.style != null))
		{
      		elm = elm.style;
      		elm[ p_property ] = p_value;
    	}
  	}

  	function setProperty(p_property, p_value) 
	{
    	setElementProperty(p_property, p_value, calendarId);
  	}

  	function getDaysInMonth(year, month) 
	{
    	return [31,((!(year % 4 ) && ( (year % 100 ) || !( year % 400 ) ))?29:28),31,30,31,30,31,31,30,31,30,31][month-1];
  	}

  	function getDayOfWeek(year, month, day) 
  	{
    	var date = new Date(year,month-1,day)
   		return date.getDay();
  	}

  	this.clearDate = clearDate;
  	function clearDate() 
	{
    	dateField.value = '';
    	hide();
  	}

  	this.setDate = setDate;
  	function setDate(year, month, day) 
	{
    	if (dateField) 
		{
      		if( month < 10 ) 
				month = "0" + month;

      		if( day < 10) 
				day = "0" + day;
	  	
      		var dateString = year + "-" + month + "-" + day ; 
      		dateField.value = dateString;
	  		hide();
    	}
    	return;
	}

	this.changeMonth = changeMonth;
  	function changeMonth(change) 
	{
    	currentMonth += change;
    	currentDay = 0;
    	if(currentMonth > 12) 
		{
      		currentMonth = 1;
      		currentYear++;
    	} 
		else if(currentMonth < 1) 
		{
      		currentMonth = 12;
      		currentYear--;
    	}
    	calendar = document.getElementById(calendarId);
    	calendar.innerHTML = calendarDrawTable();
  	}

  	this.changeYear = changeYear;
  	function changeYear(change) 
	{
    	currentYear += change;
    	currentDay = 0;
    	calendar = document.getElementById(calendarId);
    	calendar.innerHTML = calendarDrawTable();
  	}

  	function getCurrentYear() 
  	{
		var date = new Date();
    	var year =  date.getFullYear();
    	if( year < 1900 ) 
			year += 1900;
    	return year ; 
  	}

  	function getCurrentMonth() 
	{
    	return new Date().getMonth() + 1;
  	} 

  	function getCurrentDay() 
	{
    	return new Date().getDate();
  	}

  	function calendarDrawTable() 
	{
    	var dayOfMonth = 1;
    	var validDay = 0;
    	var startDayOfWeek = getDayOfWeek(currentYear, currentMonth, dayOfMonth);
    	var daysInMonth = getDaysInMonth(currentYear, currentMonth);
    	var css_class = null; //CSS class for each day

    	var table = "<table style='width:40mm' cellspacing='0' cellpadding='0' border='0'>";
    	table = table + "<tr class='header'>";
    	table = table + "  <td colspan='2' class='previous'><a href='javascript:changeCalendarControlMonth(-1);'>&lt;</a> <a href='javascript:changeCalendarControlYear(-1);'>&laquo;</a></td>";
    	table = table + "  <td colspan='3' class='title'>" + months[currentMonth-1] + "<br>" + currentYear + "</td>";
    	table = table + "  <td colspan='2' class='next'><a href='javascript:changeCalendarControlYear(1);'>&raquo;</a> <a href='javascript:changeCalendarControlMonth(1);'>&gt;</a></td>";
    	table = table + "</tr>";
    	table = table + "<tr><th>S</th><th>M</th><th>T</th><th>W</th><th>T</th><th>F</th><th>S</th></tr>";

   	 	for( var week=0; week < 6; week++ )
		{
      		table = table + "<tr>";
      		for(var dayOfWeek=0; dayOfWeek < 7; dayOfWeek++) 
			{
        		if(week == 0 && startDayOfWeek == dayOfWeek) 
          			validDay = 1; 
				else if (validDay == 1 && dayOfMonth > daysInMonth)
          			validDay = 0;

       			if(validDay) 
				{
          			if (dayOfMonth == selectedDay && currentYear == selectedYear && currentMonth == selectedMonth) 
            			css_class = 'current';

					else if (dayOfWeek == 0 || dayOfWeek == 6) 
            			css_class = 'weekend'; 
					else 
            			css_class = 'weekday';          			

          			table = table + "<td><a class='"+css_class+"' href=\"javascript:setCalendarControlDate("+currentYear+","+currentMonth+","+dayOfMonth+")\">"+dayOfMonth+"</a></td>";
          				dayOfMonth++;
        		} 
				else 
				{
          			table = table + "<td class='empty'>&nbsp;</td>";
        		}
      		}
      		table = table + "</tr>";
    	}

    	table = table + "<tr class='header'><th colspan='7' style='padding: 3px;'><a href='javascript:clearCalendarControl();'>Clear</a> | <a href='javascript:hideCalendarControl();'>Close</a></td></tr>";
    	table = table + "</table>";
    	return table;
  	}

  	this.show = show;
  	function show( field ) 
  	{
	  	can_hide = 0;
  
      	// If the calendar is visible and associated with this field do not do anything. 
     	if (dateField == field) 
      	 	return; 
	  	else 
      	 	dateField = field;

   	 	if(dateField) 
		{
      		try 
	  		{
          		var dateString = new String(dateField.value);
          		var dateParts = dateString.split("-");
        
        		selectedYear = parseInt(dateParts[0],10);
				selectedMonth = parseInt(dateParts[1],10);
        		selectedDay = parseInt(dateParts[2],10);
        		
      		} 
	  		catch(e) {}
    	}

    	if( !( selectedYear && selectedMonth && selectedDay ) ) 
		{
      		selectedMonth = getCurrentMonth();
      		selectedDay = getCurrentDay();
      		selectedYear = getCurrentYear();
    	}
    	currentMonth = selectedMonth;
    	currentDay = selectedDay;
    	currentYear = selectedYear;

    	if(document.getElementById)
		{
      		calendar = document.getElementById(calendarId);
     		calendar.innerHTML = calendarDrawTable(currentYear, currentMonth);

      		setProperty('display', 'block');

      		var fieldPos = new positionInfo(dateField);
      		var calendarPos = new positionInfo(calendarId);
      		var x = fieldPos.getElementLeft();
      		var y = fieldPos.getElementBottom();

      		setProperty('left', x + "px");
      		setProperty('top', y + "px");
 
      		if (document.all) 
			{
        		setElementProperty('display', 'block', 'CalendarControlIFrame');
        		setElementProperty('left', x + "px", 'CalendarControlIFrame');
        		setElementProperty('top', y + "px", 'CalendarControlIFrame');
        		setElementProperty('width', calendarPos.getElementWidth() + "px", 'CalendarControlIFrame');
        		setElementProperty('height', calendarPos.getElementHeight() + "px", 'CalendarControlIFrame');
      		}
    	}
  	}

  	this.hide = hide;
  	function hide() 
	{
    	if( dateField ) 
		{
      		setProperty('display', 'none');
      		setElementProperty('display', 'none', 'CalendarControlIFrame');
	  		//if( textField.onblur != true )
      		dateField = null;
    	}
  	}

  	this.visible = visible;
 	function visible()
	{
   		return dateField;
	}

  	this.can_hide = can_hide;
  	var can_hide = 0;
}



var calendarControl = new CalendarControl();

function showCalendarControl(textField) 
{
  	//textField.onblur = hideCalendarControl;
  	//if( calendarControl.visible() )
  	calendarControl.show(textField);
}

function clearCalendarControl()
{
  	calendarControl.clearDate();
}

function hideCalendarControl() 
{
  	if( calendarControl.visible() ) 
	{
    	calendarControl.hide();
  	}
}

function setCalendarControlDate( year, month, day ) 
{
  	calendarControl.setDate( year, month, day );
}

function changeCalendarControlYear(change) 
{
  	calendarControl.changeYear(change);
}

function changeCalendarControlMonth(change) 
{
  	calendarControl.changeMonth(change);
}

//document.write("<iframe id='CalendarControlIFrame' src='javascript:false;' frameBorder='0' scrolling='no'></iframe>");
document.write("<div id='CalendarControl'></div>");