@Override
  public void widgetSelected(SelectionEvent e) {

    if (retrieveMessageButton.isFocusControl()) {
      if (!clicked) {
        try {
          MessageReceiverHighLevelClass.ReceiveMessage(
              queueList.getItem(queueList.getSelectionIndex()));
          retrieveMessageButton.setText("Next Message");
          clicked = true;
        } catch (IOException e1) {
          e1.printStackTrace();
        }
      } else MessageReceiverHighLevelClass.GetNextMessage();
    } else if (closeButton.isFocusControl()) {
      MessageReceiverHighLevelClass.CloseApplication();
    }
  }