function check_date(DateValue){
				//alert(DateValue);
				var checkstr = "0123456789";
				
				var Datevalue = "";
				var DateTemp = "";
				var seperator = ".";
				var day;
				var month;
				var year;
				var leap = 0;
				var err = 0;
				var i;
				   err = 0;
	
				   if (DateValue == "000000") {
					  alert("Date is incorrect!");
					  return false;
				   }
	
				   /* Delete all chars except 0..9 */
				   for (i = 0; i < DateValue.length; i++) {
					  if (checkstr.indexOf(DateValue.substr(i,1)) >= 0) {
						 DateTemp = DateTemp + DateValue.substr(i,1);
					  }
				   }
				   DateValue = DateTemp;
				   /* Always change date to 8 digits - string*/
				   /* if year is entered as 2-digit / always assume 20xx */
				   if (DateValue.length == 6) {
					  DateValue = DateValue.substr(0,4) + '20' + DateValue.substr(4,2); }
				   if (DateValue.length != 8) {
					  err = 19;}
				   /* year is wrong if year = 0000 */
				   year = DateValue.substr(4,4);
				   if (year == 0) {
					  err = 20;
				   }
				   /* Validation of month*/
				   month = DateValue.substr(2,2);
				   if ((month < 1) || (month > 12)) {
					  err = 21;
				   }
				   /* Validation of day*/
				   day = DateValue.substr(0,2);
				   if (day < 1) {
					 err = 22;
				   }
				   /* Validation leap-year / february / day */
				   if ((year % 4 == 0) || (year % 100 == 0) || (year % 400 == 0)) {
					  leap = 1;
				   }
				   if ((month == 2) && (leap == 1) && (day > 29)) {
					  err = 23;
				   }
				   if ((month == 2) && (leap != 1) && (day > 28)) {
					  err = 24;
				   }
				   /* Validation of other months */
				   if ((day > 31) && ((month == "01") || (month == "03") || (month == "05") || (month == "07") || (month == "08") || (month == "10") || (month == "12"))) {
					  err = 25;
				   }
				   if ((day > 30) && ((month == "04") || (month == "06") || (month == "09") || (month == "11"))) {
					  err = 26;
				   }
				   /* if 00 ist entered, no error, deleting the entry */
				   if ((day == 0) && (month == 0) && (year == 00)) {
					  err = 0; day = ""; month = ""; year = ""; seperator = "";
				   }
				   /* if no error, write the completed date to Input-Field (e.g. 13.12.2001) */
				   if (err == 0) {
					  return true;
				   }
				   /* Error-message if err != 0 */
				   else {
					  alert("Date is incorrect!");
					  return false;
	
				   }
				}