function rex_backend_login($tableName)
 {
     global $REX;
     parent::rex_login();
     $this->setSqlDb(1);
     $this->setSysID($REX['INSTNAME']);
     $this->setSessiontime($REX['SESSION_DURATION']);
     $this->setUserID($tableName . '.user_id');
     $this->setUserquery('SELECT * FROM ' . $tableName . ' WHERE status=1 AND user_id = "USR_UID"');
     $this->setLoginquery('SELECT * FROM ' . $tableName . ' WHERE status=1 AND login = "******" AND psw = "USR_PSW" AND lasttrydate <' . (time() - $REX['RELOGINDELAY']) . ' AND login_tries<' . $REX['MAXLOGINS']);
     $this->tableName = $tableName;
 }