<!--- Function to Check for Valid Dates --->
function checkdate(objName) 
{
	var datefield = objName;
	if (chkdate(objName) == false) 
	{
		datefield.select();
		alert("That date is invalid. Please try again. Use mm/dd/yyyy format");
		datefield.focus();
		return false;
	}
	else 
	{
		return true;
	}
}

function chkdate(objName) 
{
	var strDatestyle = "US"; <!--- United States date style Month Day Year --->
	//var strDatestyle = "EU"; <!--- European date style Day Month Year --->
	var runTime = new Date();
	var strCurrentYear = runTime.getFullYear();
	var strDate;
	var strDateArray;
	var strDay;
	var strMonth;
	var strYear;
	var intday;
	var intMonth;
	var intYear;
	var booFound = false;
	var datefield = objName;
	var strSeparatorArray = new Array("-"," ","/",".");
	var intElementNr;
	var err = 0;
	var strMonthArray = new Array(12);
	strMonthArray[0] = "Jan";
	strMonthArray[1] = "Feb";
	strMonthArray[2] = "Mar";
	strMonthArray[3] = "Apr";
	strMonthArray[4] = "May";
	strMonthArray[5] = "Jun";
	strMonthArray[6] = "Jul";
	strMonthArray[7] = "Aug";
	strMonthArray[8] = "Sep";
	strMonthArray[9] = "Oct";
	strMonthArray[10] = "Nov";
	strMonthArray[11] = "Dec";
	strDate = datefield.value;
	if (strDate.length < 1) 
	{
		return true;
	}
	for (intElementNr = 0; intElementNr < strSeparatorArray.length; intElementNr++) 
	{
		if (strDate.indexOf(strSeparatorArray[intElementNr]) != -1) 
		{
			strDateArray = strDate.split(strSeparatorArray[intElementNr]);
			if ((strDateArray.length < 2) || (strDateArray.length > 3)) 
			{
				err = 1;
				alert('X');
				return false;
			}
			else 
			{
				strDay = strDateArray[0];
				strMonth = strDateArray[1];
				if (strDateArray.length == 2) 
					strYear = strCurrentYear ;
				else
					strYear = strDateArray[2];
			}
			booFound = true;
		}
	}
	if (booFound == false) 
	{
		if (strDate.length>5) 
		{
			strDay = strDate.substr(0, 2);
			strMonth = strDate.substr(2, 2);
			strYear = strDate.substr(4);
		}
	}

	if (strYear == null) 
	{
	  return false;
	}

	if (strYear.length == 1) 
	{
		strYear = '0' + strYear ;
	}

	if (strYear.length == 2) 
	{
		if (strYear <= 50)
			strYear = '20' + strYear;
		else
			strYear = '19' + strYear;
	}

	<!--- US style --->
	if (strDatestyle == "US") 
	{
		strTemp = strDay;
		strDay = strMonth;
		strMonth = strTemp;
	}

	intday = parseInt(strDay, 10);
	if (isNaN(intday)) 
	{
		err = 2;
		return false;
	}

	intMonth = parseInt(strMonth, 10);
	if (isNaN(intMonth)) 
	{
		for (i = 0;i<12;i++) 
		{
			if (strMonth.toUpperCase() == strMonthArray[i].toUpperCase()) 
			{
				intMonth = i+1;
				strMonth = strMonthArray[i];
				i = 12;
			}
		}
	
		if (isNaN(intMonth)) 
		{
			err = 3;
			return false;
		}
	}
	
	intYear = parseInt(strYear, 10);
	if (isNaN(intYear)) 
	{
		err = 4;
		return false;
	}
	
	if (intMonth>12 || intMonth<1) 
	{
		err = 5;
		return false;
	}
	
	if ((intMonth == 1 || intMonth == 3 || intMonth == 5 || intMonth == 7 || intMonth == 8 || intMonth == 10 || intMonth == 12) && (intday > 31 || intday < 1)) 
	{
		err = 6;
		return false;
	}
	
	if ((intMonth == 4 || intMonth == 6 || intMonth == 9 || intMonth == 11) && (intday > 30 || intday < 1)) 
	{
		err = 7;
		return false;
	}
	
	if (intMonth == 2) 
	{
		if (intday < 1) 
		{
			err = 8;
			return false;
		}
		if (LeapYear(intYear) == true) 
		{
			if (intday > 29) 
			{
				err = 9;
				return false;
			}
		}
		else 
		{
			if (intday > 28) 
			{
				err = 10;
				return false;
			}
		}
	}

	if (strDatestyle == "US") 
	{
		datefield.value = strMonthArray[intMonth-1] + " " + intday+" " + strYear;
	}
	else 
	{
		datefield.value = intday + "/" + strMonthArray[intMonth-1] + "/" + strYear;
	}
	return true;
}

function LeapYear(intYear) 
{
	if (intYear % 100 == 0) 
	{
		if (intYear % 400 == 0) 
		{ 
			return true; 
		}
	}
	else 
	{
		if ((intYear % 4) == 0) 
		{ 
			return true; 
		}
	}
	return false;
}