$(function () {
    // validate the zip input when main form when it is submitted
    $("#zip-form").validate({
        submitHandler: function (form) {
            tracksubmit(form.name, $("input[name='mode']", form).val(), $("select[name='service']", form).val());
            form.submit();
        },
        rules: {
            zipcode: {
                required: true,
                digits: true,
                minlength: 5
            }
        },
        messages: {
            zipcode: ""
        }
    });
});