How to add a button to an existing frame?

Question

Hey everyone , this is a GUI question for a project I am doing in school.
Basically, I have created a frame that has 3 JPanes, top, center and bottom. Here are the declarations:
this.add(northPanel,    BorderLayout.NORTH);
          this.add(SYBoard, BorderLayout.CENTER);
          this.add(southPanel,    BorderLayout.SOUTH);          
                When I try to add a button to the top panel, nothing is happening. This is my first time with GUI, so if anyone knows what is wrong, I wold highly appreciate it. Thanks so much:
     private void startGame() {
          String playerName = JOptionPane.showInputDialog("Enter your name");
          System.out.println(playerName);
          ScotlandYard.frame.northPanel.add(new JButton(playerName));
          ScotlandYard.frame = new SYFrameWithImages();
          ScotlandYard.frame.update();
          this.repaint();
     }               as you can see, i have tried updating, repainting, etc, but nuthin' is happening.

Answer 1

In the future, Swing related questions should be posted in the Swing forum.
After adding/removing a component from a panel on a visible frame you need to do:
panel.add(...);
panel.revalidate();
panel.repaint(); // generally only needed for a remove