function editDay(fieldname,month,day,year, monthDayLength) {

	if (!(isNumeric(day))) {
		passed = false;
		errorMessage = errorMessage + fieldname + " day must be numeric."  + CRLF;
	} else {
		if (monthDayLength == 2) {
			strDay = day.toString();
			if (strDay.length < 2) {
				passed = false;
				errorMessage = errorMessage + fieldname + " day must be 2 digits long." + CRLF;
			}
		} else {
			if ((day < 1) || (day > 31)) {
				passed = false;
				errorMessage = errorMessage + fieldname + " day must be between 1 and 31."  + CRLF;
			} else {
				if (month == 2)	{
					if (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0)) { 
						if (day > 29) { 
							passed = false;
							errorMessage = errorMessage + fieldname + " day must be less than 30 for February."  + CRLF;
						}	else { 
							if (day > 28) {
								passed = false;
								errorMessage = errorMessage + fieldname + " day must be less than 29 for February."  + CRLF;
							} 
						}
					}
				}
				if ((month == 4) || (month == 6) || (month == 9) || (month == 11)) {
					if (day > 30) {
						passed = false;
						errorMessage = errorMessage + fieldname + " day must be less than 31 for this month."  + CRLF;
					}
				}
			}
		}
	}
	
}