protected JPanel buildButtonPanel() {
    JPanel pnl = new JPanel(new FlowLayout(FlowLayout.CENTER));

    // -- apply button
    ApplyAction applyAction = buildApplyAction();
    pnlTagConflictResolver.getModel().addPropertyChangeListener(applyAction);
    pnlRelationMemberConflictResolver.getModel().addPropertyChangeListener(applyAction);
    btnApply = new SideButton(applyAction);
    btnApply.setFocusable(true);
    pnl.add(btnApply);

    // -- cancel button
    CancelAction cancelAction = new CancelAction();
    pnl.add(new SideButton(cancelAction));

    // -- help button
    helpAction = new ContextSensitiveHelpAction();
    pnl.add(new SideButton(helpAction));

    return pnl;
  }
 protected void makeButtonRespondToEnter(SideButton btn) {
   btn.setFocusable(true);
   btn.getInputMap(JComponent.WHEN_FOCUSED)
       .put(KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0), "enter");
   btn.getActionMap().put("enter", btn.getAction());
 }