function checkdate(objName)
{
	var datefield = objName;
	if (chkdate(objName) == false)
	{
		datefield.select();
		alert("Date value '" + objName.value + "' is an invalid date.");
		datefield.focus();
		return false;
	}
	else
	{
		return true;
	}
}

function chkdate(objName)
{
	//var strDatestyle = "US"; //United States date style
	var strDatestyle = "EU";  //European date style
	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)||(strDate=="dd-mon-yyyy"))
	{	return true;	}

	for (intElementNr = 0; intElementNr < strSeparatorArray.length; intElementNr++)
	{
		if (strDate.indexOf(strSeparatorArray[intElementNr]) != -1)
		{
			strDateArray = strDate.split(strSeparatorArray[intElementNr]);
			if (strDateArray.length != 3)
			{
				err = 1;
				return false;
			}
			else
			{
				strDay = strDateArray[0];
				strMonth = strDateArray[1];
				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) && (strYear.length == 2) )
	{
		strYear = '20' + 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;
}