function validDay(sDate)                                                 //
{
	//get the month, day and year portions of 'sDate'
	var month=getMonth(sDate);
	var day=getDay(sDate);
	var year=getYear(sDate);
	
	//get the number of days in 'month'
	var max=daysInMonth(month,year);
	
	//make sure 'day' is a number
	if(day!=parseInt(day))return false;
	
	//determine whether or not 'day' is valid
	if((day<1)||(day>max))return false;
	return true;
}