function validateForm() {
	if((document.mailingList.email.value.length==0) || (document.mailingList.zip.value.length==0)) {
		formError();
		alert("Please fill in required fields.");
		return false;
	} else {
		document.mailingList.submit();
	}
}

function formError() {
	var input = new Array(document.mailingList.email, document.mailingList.zip);
	var spans = new Array('emailLabel', 'zipLabel');
	executeError(input, spans);
	return false;
	
}

function executeError(input, spans) {
	for (var i=0; i<input.length; i++) {
		document.getElementById(spans[i]).style.color = "#000";
		if (input[i].value.length==0) {
			document.getElementById(spans[i]).style.color = "#f00";
		}
	}
}