public function open($savePath, $sessionName)
    {
        $sql  = 'INSERT INTO tbl_sessions (SESSION_ID, SESSION_DATA) values (:SESSID, :SESSDATA) ON DUPLICATE KEY UPDATE LAST_ACCESSED=NOW()';
        $stmt = $this->_db->prepare($sql);
        $stmt->execute(array(':SESSID' => session_id(), ':SESSDATA' => ''));

    }