// JavaScript Document
function validateZIP(field) {
var valid = "0123456789-";
var hyphencount = 0;

if (field.length!=5 && field.length!=10) {
alert("Please Enter Valid 5 Digit 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("Please Enter Valid Zip Code");
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;
}