var EZcalendar = false;     // Loaded or not?
 var bCalendarFade = false;  // Fade in or not? Not suitable for slow machines
 var iCalendarFadeSpd = 25;  // Lower the number, faster it is.
 var selectedDate;           // whether the users cursor is over the calendar
 var target;                 // the target element for the date value
 var dateSeparator = "/";    // date separator unit 
 var overCalendar = false;   // whether the users cursor is over the calendar
 var shortMonths = new Array("Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec");
 var fullMonths = new Array("January","February","March","April","May","June","July","August","September","October","November","December");
 var left;
 var top;
 // simply return an object by id
 function getID(id) {
 return document.getElementById(id);
 }
 function getName(name,ret_idx) {
 if(document.getElementsByName(name).length>0)   return document.getElementsByName(name)[ret_idx];
 }
 // return a number with 2 digits ("2" becomes "02")
 function formatNumber(n) {
     return (n<10) ? "0"+n : n;
 }
 function getScrollFromTop() {
     if (self.pageYOffset) {
         return self.pageYOffset;
     } else if (document.documentElement && document.documentElement.scrollTop) {
         return document.documentElement.scrollTop;
     } else {
         return document.body.scrollTop;
     }    
  }
 // return a number > 10 as one single digit ("09" becomes "9")
 function removeFormatNumber(n) {
     return (n.substr(0,1)=="0") ? n.substr(1,1) : n;
 }
 // return the on-screen LEFT(x) position of an element
  function getPageOffsetLeft(el) {
     return (el.offsetParent != null) ? el.offsetLeft + getPageOffsetLeft(el.offsetParent) : el.offsetLeft;
  }
 // return the on-screen TOP(y) position of an element    
 function getPageOffsetTop(el) {
     return (el.offsetParent != null) ? el.offsetTop + getPageOffsetTop(el.offsetParent) : el.offsetTop;
 }
 // Checks a string to see if it in a valid date format
 // of (D)D/(M)M/(YY)YY and returns true/false
 function isValidDate(s) {
    // format D(D)/M(M)/(YY)YY
     var dateFormat = /^\d{1,2}\/\d{1,2}\/\d{1,4}$/;
     if (dateFormat.test(s)) {
         // remove any leading zeros from date values
         s = s.replace(/0*(\d*)/gi,"$1");
         var dateArray = s.split("/");
         // correct month value
         dateArray[0] = dateArray[0]-1;
         // correct year value
         if (dateArray[2].length<4) {
             // correct year value
            dateArray[2] = (parseInt(dateArray[2]) < 50) ? 2000 + parseInt(dateArray[2]) : 1900 + parseInt(dateArray[2]);
 		}
 		var testDate = new Date(dateArray[2], dateArray[0], dateArray[1]);
 		if (testDate.getDate()!=dateArray[1] || testDate.getMonth()!=dateArray[0] || testDate.getFullYear()!=dateArray[2]) {
 			return false;
 		} else {
 			return true;
 		}
 	} else {
 		return false;
 	}
 }
 // get the calendar week of a date
 function getWeek(d) {
 	/* thanks to http://www.quirksmode.org/js/week.html */
 	var today = new Date(d);
 	Year = today.getFullYear();
 	Month = today.getMonth();
 	Day = today.getDate();
 	now = Date.UTC(Year,Month,Day+1,0,0,0);
 	var Firstday = new Date();
 	Firstday.setYear(Year);
 	Firstday.setMonth(0);
 	Firstday.setDate(1);
 	then = Date.UTC(Year,0,1,0,0,0);
 	var Compensation = Firstday.getDay();
 	if (Compensation > 3) Compensation -= 4;
 	else Compensation += 3;
 	NumberOfWeek =  Math.round((((now-then)/86400000)+Compensation)/7);
 	return formatNumber(NumberOfWeek);
 }
 // change the calendar to the PREVIOUS month
 function prevMonth() {
 	var months = getID("months");
 	var years = getID("years");
 	if (parseInt(months.value) - 1 >= 0) {
 		months.value = parseInt(months.value) - 1;
 	} else if (parseInt(years.value) > 1901) {
 		months.value = 11;
 		years.value = parseInt(years.value) - 1;
 	}
 	updateCalendar();	
 }
 // change the calendar to the NEXT month
 function nextMonth() {
 	var months = getID("months");
 	var years = getID("years");
 	if (parseInt(months.value) + 1 < 12) {
 		months.value = parseInt(months.value) + 1;
 	} else if (parseInt(years.value) < 2099) {
 		months.value = 0;
 		years.value = parseInt(years.value) + 1;
 	}
 	updateCalendar();	
 }
 // change the calendar to the PREVIOUS year
 function prevYear() {
 	var years = getID("years");
 	if (parseInt(years.value) > 1901) {
 		years.value = parseInt(years.value) - 1;
 	}
 	updateCalendar();	
 }
 // change the calendar to the NEXT year
 function nextYear() {
 	var years = getID("years");
 	if (parseInt(years.value) < 2099) {
 		years.value = parseInt(years.value) + 1;
 	}
 	updateCalendar();	
 }
 // update the calendars values
 // this changes the <a> tags innerHTML and href values
 function updateCalendar() {
 	var today = new Date();
 	var y = getID("years");
 	var m = getID("months");
 	y = y.value;
 	m = m.value;
 	var calendarDate = new Date(y,m,1);
 	getID("EZcalendar_text").innerHTML =  shortMonths[calendarDate.getMonth()] + " " + calendarDate.getFullYear();
 	var defaultMonth = calendarDate.getMonth();
 	var difference = calendarDate.getDay();
 	calendarDate.setDate(calendarDate.getDate()-difference);
 	for (r=0;r<6;r++) {
 			for (c=0;c<7;c++) {
 				if (calendarDate.getMonth()!=defaultMonth) {
 				//hide text if they are out of current month
 					getID("cell"+r+c).className="outsideMonth";
 				} else {
 					getID("cell"+r+c).className="";
 				}
 				// is it today's date?
 				if (calendarDate.getDate()+"/"+calendarDate.getMonth()+"/"+calendarDate.getFullYear()==today.getDate()+"/"+today.getMonth()+"/"+today.getFullYear()) {
 					getID("cell"+r+c).className="today";
 				}
 				if (calendarDate.getMonth()==defaultMonth) 
 				{
 				getID("cell"+r+c).title = "";
 				getID("cell"+r+c).innerHTML = calendarDate.getDate();	
 				getID("cell"+r+c).href = "javascript:setDateValue('" + formatNumber(calendarDate.getMonth()+1) + dateSeparator +  formatNumber(calendarDate.getDate()) + dateSeparator + calendarDate.getFullYear() + "')";
 				getID("cell"+r+c).title = calendarDate.getDate() + " " + fullMonths[calendarDate.getMonth()] + ", " + calendarDate.getFullYear();
 				}
 				else
 				{
 				getID("cell"+r+c).innerHTML = " ";	
 				}
 				calendarDate.setDate(calendarDate.getDate()+1);
 			}
 	}
 }
 // when a user click the show calendar link, this function opens 
 // the calendar and tries to show the correct calendar for the date in
 // the input field.
 function showCalendar(el,top,left,idx) { 
 	if (EZcalendar) {
 		if (typeof el == "string") {
 			var el = getName(el,idx); 
 		} 
 target=el;
 		var y = getID("years");
 		var m = getID("months");
 		var calendar = getID("EZcalendar");
 		// test if string is valid date and if so, show calendar relative to the date they have chosen.
 		if (isValidDate(target.value)) {
 			var elDate = target.value.replace(/0*(\d*)/gi,"$1");
 			var dateArray = elDate.split(dateSeparator);
 			// correct month value
 			dateArray[0] = dateArray[0]-1;
 			if (dateArray[2].length<4) {
 				// correct year value
 				dateArray[2] = (parseInt(dateArray[2]) < 50) ? 2000 + parseInt(dateArray[2]) : 1900 + parseInt(dateArray[2]);
 			}
 			m.value = dateArray[0];
 			y.value = dateArray[2];
 		} else {
 			m.value = selectedDate.getMonth();
 			y.value = selectedDate.getFullYear();
 		}
 		updateCalendar();
 		var x = getPageOffsetLeft(el);
 		var y = getPageOffsetTop(el) + el.clientHeight;	
 		if(left>=0)
 		calendar.style.left = left+"px";
 		else
 		calendar.style.left = x+"px";	
 		if(top>=0)	
 		calendar.style.top = top+"px";
 		else
 		calendar.style.top = (y+5)+"px";
 		if (bCalendarFade) {
 			calendar.style.opacity = 0;
 			calendar.style.filter = "alpha(opacity=0)";
 			calendar.MozOpacity = 0;
 			calendar.KhtmlOpacity = 0;
 			setTimeout("fadeIn(5)",iCalendarFadeSpd);
 		}
 		calendar.style.display = "block";
 	} else {
 		alert("NOTICE:\n\nCalendar not finished loading, please wait...");	
 	}
 }
 /* When the user clicks, this function tries to detect 
 if they have clicked outside the calendar and if so 
 it tries to hide it. */
 function clickbg(e) {
 	if (!overCalendar) {
 		getID("EZcalendar").style.display="none";
 	}
 }
 /* When a user click the calendar date, this function updates the input field */
 function setDateValue(d,el) {
 	if (bCalendarFade) {
 		setTimeout("fadeOut(95)",iCalendarFadeSpd);
 	} else {
 		getID("EZcalendar").style.display = "none";
 	}
 	target.value=d;
 }
 /* Fading in the calendar in a nice way */
 function fadeIn(percentage) {
 	var EZcalendar = getID("EZcalendar");
 	// apply opacity for all browsers
 	EZcalendar.style.opacity = percentage/100;
 	EZcalendar.style.filter = "alpha(opacity="+percentage+")";
 	EZcalendar.MozOpacity = (percentage / 100);
 	EZcalendar.KhtmlOpacity = (percentage / 100);	
 	if (percentage<100) {
 		setTimeout("fadeIn("+(percentage+5)+")",iCalendarFadeSpd);
 	}
 }
 /* Fading in the calendar in a nice way */
 function fadeOut(percentage) {
 	var EZcalendar = getID("EZcalendar");
 	// apply opacity for all browsers
 	EZcalendar.style.opacity = percentage/100;
 	EZcalendar.style.filter = "alpha(opacity="+percentage+")";
 	EZcalendar.MozOpacity = (percentage / 100);
 	EZcalendar.KhtmlOpacity = (percentage / 100);	
 	if (percentage>0) {
 		setTimeout("fadeOut("+(percentage-5)+")",iCalendarFadeSpd);
 	} else {
 		EZcalendar.style.display = "none";
 	}
 }
 /* Loads the calendar for the first time by creating all the HTML */
 function initCalendar() {
 	var calendarDate = new Date;
 	// create our container DIV and add javascript to it
 	var EZCalendarDIV = document.createElement('div');
 	EZCalendarDIV.id = "EZcalendar"; 
 	EZCalendarDIV.onmouseover = function() { overCalendar=true; }
 	EZCalendarDIV.onmouseout  = function() { overCalendar=false; }
 	// hide calendar by default
 	EZCalendarDIV.style.display = "none";
 	document.body.appendChild(EZCalendarDIV);
 	var calendarHTML = "";
 	selectedDate = new Date();
 //	calendarHTML += '<form action="#" method="get">';
 	calendarHTML += '	<input id="months" name="months" type="hidden" value="' + selectedDate.getMonth() + '" />';
 	calendarHTML += '	<input id="years" name="years" type="hidden" value="' + selectedDate.getFullYear() + '" />';
 	calendarHTML += '	<div id="EZcalendar_table">';
 	calendarHTML += '		<table border="1" cellpadding="0" cellspacing="0">';
 	calendarHTML += '			<tr>';
 	calendarHTML += '				<td><input type="button" value="&laquo;" onclick="prevYear()" title="Previous Year" /></td>';
 	calendarHTML += '				<td><input type="button" value="&lsaquo;" onclick="prevMonth()" title="Previous Month" /></td>';
 	calendarHTML += '				<td colspan="3" id="EZcalendar_text">' + shortMonths[selectedDate.getMonth()] + " " + selectedDate.getFullYear() + '</td>';
 	calendarHTML += '				<td><input type="button" value="&rsaquo;" onclick="nextMonth()" title="Next Month" /></td>';
 	calendarHTML += '				<td><input type="button" value="&raquo;" onclick="nextYear()" title="Next Year" /></td>';
 	calendarHTML += '			</tr>';
 	// build table using for loops...		
 	calendarHTML += '			<tr>';
 	calendarHTML += '				<th scope="col">S</th>';
 	calendarHTML += '				<th scope="col">M</th>';
 	calendarHTML += '				<th scope="col">T</th>';
 	calendarHTML += '				<th scope="col">W</th>';
 	calendarHTML += '				<th scope="col">T</th>';
 	calendarHTML += '				<th scope="col">F</th>';
 	calendarHTML += '				<th scope="col">S</th>';
 	calendarHTML += '			</tr>';
 	var defaultMonth = calendarDate.getMonth();
 	for (r=0;r<6;r++) {
 		calendarHTML += '	<tr>';
 			for (c=0;c<7;c++) {
 			   if (calendarDate.getMonth()==defaultMonth) {
 				calendarHTML += '		<td><a href="#" id="cell'+ r + "" + c +'"></a></td>';	
 				}
 				else
 				{
 					calendarHTML += '		<td></td>';		
 				}
 			}
 	}
 	calendarHTML += '	</tr>';	
 	calendarHTML += '</table>';
 	calendarHTML += '<br/><center><a href="#" id="seltoday" class="seltoday" onclick=javascript:setDateValue("'+  formatNumber(calendarDate.getMonth()+1) + dateSeparator + formatNumber(calendarDate.getDate())+ dateSeparator + calendarDate.getFullYear() + '") >Today</a></center>';
 	// ... end 
 	calendarHTML += '	</div>';
 	EZCalendarDIV.innerHTML = calendarHTML;
 	EZcalendar = true;
 	document.onmousedown = clickbg;
 	updateCalendar();
 }
 /* Initialise the page by preparing the calendar when the page has loaded */
 document.onload = setTimeout("initCalendar()",500);