function isDateFormatValid(dateStr)
{
	if (dateStr == "")
	{
		alert("Please enter a date.");
		return false;
	}
	else
	{
		var datePat = /^(\d{1,2})(\/)(\d{1,2})\2(\d{4})$/;

		var matchArray = dateStr.match(datePat);

		if (matchArray == null)
		{
			alert(dateStr + " is not a valid MM/DD/YYYY format.");
			return false;
		}

		var month = matchArray[1];
		var day = matchArray[3];
		var year = matchArray[4];

		if (month < 1 || month > 12)
		{
			alert("Month must be between 1 and 12.");
			return false;
		}

		if (day < 1 || day > 31)
		{
			alert("Day must be between 1 and 31.");
			return false;
		}

		if ((month==4 || month==6 || month==9 || month==11) && day==31)
		{
			alert("Month "+month+" doesn't have 31 days.");
			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))
			{
				alert("February " + year + " doesn't have " + day + " days.");
				return false;
			}
		}
		return true;
	}
}