is_ajax(){return($_SERVER["HTTP_X_REQUESTED_WITH"]=="XMLHttpRequest");}function
redirect($_,$B=null){if($B!==null){restart_session();$_SESSION["messages"][preg_replace('~^[^?]*~','',($_!==null?$_:$_SERVER["REQUEST_URI"]))][]=$B;}if($_!==null){if($_=="")$_=".";header("Location: $_");exit;}}function