function isaDate(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) {
		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.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;
		}
	  }
	}
	return true;
}

function LeapYear(intYear) {
  if (intYear % 100 == 0) {
    if (intYear % 400 == 0) { 
	  return true; 
	}
  }
  else {
    if ((intYear % 4) == 0) { 
	  return true; 
	}
  }
  return false;
}