function clearInput(el) {if (el.defaultValue==el.value) el.value = "";}
function isNumeric(sText){
		var ValidChars = "0123456789";
		var IsNumber = true;
		var Char;
		
		for (i = 0; i < sText.length && IsNumber == true; i++){ 
			Char = sText.charAt(i); 
			if(ValidChars.indexOf(Char) == -1){
				IsNumber = false;
			}
		}
		return IsNumber;
	}

function validateZipCode(field,zipID) {
	var zipField = document.getElementById(zipID);
	
	if (field.length < 5 || field.length > 5 || field == "00000" || field == "99999") {
		
		alert("Please enter a valid 5 digit zip code.");
		zipField.focus();
		return false;
	} 
	if(!isNumeric(field)){
			alert("Please enter a valid zip code.");
			zipField.focus();
			return false;
	}
	
	return true;
}