throw new Error("rootPaneChecking is enabled - cannot set layout.");
throw new Error("Cannot set top-level layout.  Use" + " getConentPane().setLayout instead."); getContentPane().setLayout(manager); } else
  public  void setLayout(LayoutManager manager)  {    if (isRootPaneCheckingEnabled())      throw new Error("rootPaneChecking is enabled - cannot set layout.");    super.setLayout(manager);  }