Well, I use a JFrame that adds two JPanels. Those JPanels are superclasses, because I find it easier to separate different areas of the GUI into different classes. But here's the problem:

1. I add the (superclass) JPanel to the JFrame
2. I set the layout of the superclass JPanel to new BorderLayout();

3. I add components in the subclasses, like this:

   JPanel panel = new JPanel();
   panel.setLayout(new GridLayout(2,1));
   panel.add(new JLabel("Label:"); panel.add(new JTextField();
   add(panel, BorderLayout.NORTH);

But it doesn't show. What do I do wrong? I've tried it without an additional JPanel in the subclasses, but it doesn't work either. I use jdk 1.6