// ******************************************************************
// This function accepts a string variable and verifies if it is a
// proper date or not. It validates format matching either
// mm-dd-yyyy or mm/dd/yyyy. Then it checks to make sure the month
// has the proper number of days, based on which month it is.

// The function returns true if a valid date, false if not.
// ******************************************************************
	
function checkDate(dateStr) {
	var datePat = /^(\d{1,2})(\/|-)(\d{1,2})(\/|-)(\d{4})$/;
	var matchArray = dateStr.match(datePat); // is the format ok?
	
	if (matchArray == null) {
	return false;
	}
	
	month = matchArray[1]; // p@rse date into variables
	day = matchArray[3];
	year = matchArray[5];
	
	if (month < 1 || month > 12) { // check month range
		return false;
	}
	
	if (day < 1 || day > 31) {
		return false;
	}
	
	if ((month==4 || month==6 || month==9 || month==11) && day==31) {
		return false;
	}
	
	if (month == 2) { // check for february 29th
		var isleap = (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
		if (day > 29 || (day==29 && !isleap)) {
			return false;
		}
	}
	return true; // date is valid
}