(function($) {

    $.validator.addMethod("housenumber", function(value, element) {
        return this.optional(element) || /^[a-zA-Z0-9]{0,6}$/.test(value);
    }, "ongeldig");

    $.validator.addMethod("postcode", function(value, element) {
        return this.optional(element) || /^([0-9]{4}(\s)?[a-zA-Z]{2})?$/.test(value);
    }, "ongeldig");

    $.validator.addMethod("telephone", function(value, element) {
        return this.optional(element) || /^(\+)?([0-9\s\-]{5,12})?$/.test(value);
    }, "ongeldig");

    $.extend(jQuery.validator.messages, {
        required: "verplicht",
        email: "ongeldig",
        equalTo: "onjuist"
    });

})(jQuery);