function y2k(number) { return (number < 1000) ? number + 1900 : number; }

function CorrectDate(day,month,year) {
    var today = new Date();
    year = ((!year) ? y2k(today.getYear()):year);
    month = ((!month) ? today.getMonth():month-1);
    if (!day) return false
    var test = new Date(year,month,day);
    if ( (y2k(test.getYear()) == year) &&
         (month == test.getMonth()) &&
         (day == test.getDate()) )
       {return true;}
    else
       {return false;}
}

function CheckRegex(object_value, regex) {
	return regex.test(object_value);
}


function isDate(listname,formNR,messageText) {
	var date = new Date();
	var d  = date.getDate();
	var dd = (d < 10) ? '0' + d : d;
	var m = date.getMonth() + 1;
	var mm = (m < 10) ? '0' + m : m;
	var yy = date.getYear();
	var yyyy = (yy < 1000) ? yy + 1900 : yy;
	
	var now = dd + "/" + mm + "/" + yyyy
	var nowwrong = d + "/" + m + "/" + yy

	for (var i = 0; i < listname.length; i++)
	{
		var theDate = document.forms[formNR].elements[listname[i]].value;
		if (theDate != '') 
		{
			//var objRegExp = /^\d{2}(\-|\/|\.)\d{2}\1\d{4}$/
			var objRegExp = /^\d{2}(\/)\d{2}\1\d{4}$/

			//check to see if in correct format
			if(!objRegExp.test(theDate))
			{
				alert ('OPMERKING\nHet volgende veld moet een datum zijn: ' + messageText[i] + '\nIn het volgende formaat ('+now+'), dus niet ('+nowwrong+')')
				document.forms[formNR].elements[listname[i]].focus()
				return false;
				break
			}
			else
			{
				var dateArray = theDate.split('/');
				if (dateArray[2].length != 4 || !CorrectDate(dateArray[0],dateArray[1],dateArray[2]))
				{
					alert ('OPMERKING\nHet volgende veld moet een datum zijn: ' + messageText[i] + '\nIn het volgende formaat ('+now+'), dus niet ('+nowwrong+')')
					document.forms[formNR].elements[listname[i]].focus()
					return false;
				}
			}
		}
	}
return true;
}

function datecompare(start,end) {
	if (start.value != '' && end.value != '') {
		var aStart = start.value.split('/');
		var aEnd = end.value.split('/');
		/* Convert dates to numbers for comparison */
		startTmp = aStart[2] + '' + aStart[1] + '' + aStart[0];
		endTmp = aEnd[2] + '' + aEnd[1] + '' + aEnd[0];
		//alert(startTmp +' | '+ endTmp);
		if (startTmp > endTmp) {
			alert('OPMERKING\nDe einddatum is eerder dan de startdatum')
			start.focus();
			return false;
		}
	}
return true;
}