private void mRemoveNode() {
    String old_node = (String) lstNodes.getSelectedValue();

    java.util.List remove_list =
        ConfigUtilities.getElementsWithDefinition(mBroker.getElements(mContext), old_node);
    for (int i = 0; i < remove_list.size(); i++) {
      mBroker.remove(mContext, (ConfigElement) remove_list.get(i));
    }
  }
  private void mAddNodeBtn_actionPerformed(ActionEvent e) {
    String host_name = mHostnameField.getText().trim();
    String element_name = "Node(" + host_name + ")";
    java.util.List elts = mBroker.getElements(mContext);
    java.util.List matches = ConfigUtilities.getElementsWithDefinition(elts, element_name);

    if (!host_name.equals("") && matches.size() == 0) {
      // Create a cluster_node element for the node
      ConfigElementFactory factory =
          new ConfigElementFactory(mBroker.getRepository().getAllLatest());
      ConfigElement element = factory.create(element_name, CLUSTER_NODE_TYPE);
      mBroker.add(mContext, element);
      element.setProperty("host_name", 0, host_name);
      element.setProperty("listen_port", 0, "7000");
    }
    mHostnameField.setText("");
  }