			$dLastVisit =	date("Ymdhi", strtotime($this->get_session("last_visit"))); 
			$dExpTime 	=	date("Ymdhi", strtotime("-".SESSEXP." minutes"));

			if (!empty($dLastVisit)) {
				if ($dLastVisit > $dExpTime) {
					$this->set_session("last_visit", date("YmdHi"));
					return true;
				} else {
					return true;
				}