public function logout($reason=null) {
		global $USER;
		if( !$this->login ) {
// 			debug('user is not logged in');
			return false;
		}
		$this->login = self::NOT_LOGGED;
		$_SESSION['USER'] = $USER = null;
		$_SESSION['LOGOUT_REASON'] = $reason;
		//debug('Session updated');
		return true;
	}