function validDate(dateStr)
{
	var datePat = /^(\d{1,2})(\/)(\d{1,2})(\/)(\d{2}|\d{4})$/;

	var matchArray = dateStr.match(datePat); 
		
	if (matchArray == null)
	 {
		return false;
	 }

	month = matchArray[1]; // parse 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;
		}
	}
	
	if (year.length == 2) 
	{
		if (Number(year)<50 && Number(year)>=0)
			year = "20" + year;
		else
			year = "19" + year;
	}
	
	if (year.length != 4) 
		return false;
	
	if (year < "1901")
		return false;

	return true;  // date is valid
}