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));
    }
  }
  public void init(Map whiteboard) {
    mWhiteBoard = whiteboard;

    // Get handle to broker
    mBroker = new ConfigBrokerProxy();

    // Create a context
    mContext = (ConfigContext) mWhiteBoard.get("context");

    mNodesListModel = new ConfigPtrListModel(mContext);
    mNodesListModel.addElementType(CLUSTER_NODE_TYPE);
    mBroker.addConfigListener(mNodesListModel);
    lstNodes.setModel(mNodesListModel);

    mHostnameField.setText("");
  }