jQuery.validator.addMethod("dateNL", function(value, element) {
		var check = false;
		var re = /^\d{1,2}\/\d{1,2}\/\d{4}$/;
		if( re.test(value)){
			var adata = value.split('/');
			var gg = parseInt(adata[0],10);
			var mm = parseInt(adata[1],10);
			var aaaa = parseInt(adata[2],10);
			var xdata = new Date(aaaa,mm-1,gg);
			if ( ( xdata.getFullYear() == aaaa ) && ( xdata.getMonth () == mm - 1 ) && ( xdata.getDate() == gg ) )
				check = true;
			else
				check = false;
		} else
			check = false;
		return this.optional(element) || check;
	}, "Vul hier een geldige datum in."
);

jQuery.validator.addMethod("numberNL", function(value, element) {
	    return this.optional(element) || /^-?(?:\d+|\d{1,3}(?:\.\d{3})+)(?:,\d+)?$/.test(value);
    }, "Vul hier een geldig nummer in."
);

    jQuery.validator.addMethod("noHTML", function(value, element) {
    return this.optional(element) || ! /<.[^<>]*?>/i.test(value);
    }, "Sorry, no HTML allowed."
);