function form_validation(name) {	
	var req = new Request.HTML({url:'inc/kasse/ajax/validate.php?name=' + name + '&value=' + encodeURIComponent($(name).value), 
		onSuccess: function(html) {
			$('val_'+name).set('text', '');
			$('val_'+name).adopt(html);
		}
	}).send();
}