//Function can be used for checking valid date in case of 3 select lists for day month year.
function isDate(d,m,y)
{
	// check for February
	if ((m == 2) && (d > 29)) 
	{ return false; }
	if ((m == 2) && (d == 29)) 
	{
		var div4 = y % 4;
		var div100 = y % 100;
		var div400 = y % 400;
		// if not divisible by 4, then not a leap year so Feb 29 is invalid
		if (div4 != 0) { return false; }
		// at this point, year is divisible by 4. So if year is divisible by
		// 100 and not 400, then it's not a leap year so Feb 29 is invalid
		if ((div100 == 0) && (div400 != 0)) { return false; }
	}
	// check for months with only 30 days
	if ((m == 4) || (m == 6) || (m == 9) || (m == 11)) 
	{ 
		if (d > 30) { return false; } 
	}
	// date is valid
	return true;
}