function validateField(field_el, default_text){
	if(field_el.value=="" || field_el.value==default_text){
		field_el.style.background="red";
		field_el.style.color="white";
		return 0;
	} else {
		field_el.style.background="white";
		field_el.style.color="black";
		return 1;
	}
}

function validateZip(field) {
	var valid = "0123456789";
	var hyphencount = 0;
	var temp;
	
	if (field.length!=5) {	
		return false;
	}
	
	for (var i=0; i < field.length; i++) {
		temp = "" + field.substring(i, i+1);
		if (valid.indexOf(temp) == "-1") {
			alert("Invalid characters in your zip code.  Please try again.");
			return false;
		}
	}
	return true;
}