private void gameNameChanged() {
    if (client.getCommunicator() != null) {
      popUpWindow dialog = new popUpWindow(this, "Wollen Sie sich wirklich vom Server abmelden ?");

      if (dialog.getResult()) {
        client.disconnect();
      }
    }

    if (client.getCommunicator() == null) {
      isGameLoaded = (theGameClass.getText().length() > 0);

      if (isGameLoaded && isServerOk && isPortOk) {
        connectToServer.setEnabled(true);
      } else {
        connectToServer.setEnabled(false);
      }
    } else {
      theGameClass.setText(client.getProtocolName());
    }
  }