function clean()
        {
            if ($this->result = $GLOBALS['db']->query("SELECT * FROM chat WHERE 1 = 1 GROUP BY chatid")) {
                foreach ($this->result as $key => $val) {
                    if (!$GLOBALS['db']->query("SELECT * FROM sessions WHERE chatid='".$this->result[$key]['chatid']."'")) {
                        $this->result2 = $GLOBALS['db']->query("SELECT * FROM chat WHERE chatid='".$this->result[$key]['chatid']."' ORDER BY timestamp DESC LIMIT 1");
                        if ($this->result2[0]['timestamp'] < (time() - 3600)) {
                            $GLOBALS['db']->query("DELETE FROM chat WHERE chatid='".$this->result[$key]['chatid']."'");
                        }
                    }
                }
            }
        }