window.addEvent('domready', function() {
	$$('FORM.validate').addEvent('submit', function() {
		$(this).getElements('.required').each(function(el) {
			$(el)[$(el).get('value') == '' ? 'addClass' : 'removeClass']('invalid');
		});
		var invalid = $(this).getElements('.invalid');
		if (invalid.length > 0) {
			invalid[0].focus();
		}
		return invalid.length == 0;
	});
});