function quit($force=false) {
    if($this->_ready) {
      if(!$this->_exec("QUIT") and !$force) return FALSE;
      if(!$this->ftp_base::_checkCode() and !$force) return FALSE;
      $this->_ready=false;
      $this->ftp_base::SendMSG("Session finished");
    }
    $this->_quit();
    return TRUE;
  }