//Edited: 7/13/2007
//Author:  Brett Ackerman
//Comment:
//This validates for US Zip Codes Only

function zipValidation(objField)
{
	var field = objField.value;
	var valid = "0123456789-";
	var hyphencount = 0;

	if(field==""){
		return true;
	}

	if (field.length!=5 && field.length!=10) {
		alert("Please enter your 5 digit or 5 digit+4 zip code.");
		return false;
	}
	for (var i=0; i < field.length; i++) {
		temp = "" + field.substring(i, i+1);
		if (temp == "-") hyphencount++;
		if (valid.indexOf(temp) == "-1") {
			alert("Invalid characters in your zip code.  Please try again.");
			return false;
		}
		if ((hyphencount > 1) || ((field.length==10) && ""+field.charAt(5)!="-")) {
			alert("The hyphen character should be used with a properly formatted 5 digit+four zip code, like '12345-6789'.   Please try again.");
			return false;
		}
	}
	return true;
}