Voice Mail System GUI

• Arrange keys in panel with GridLayout:
  

  JPanel keyPanel = new JPanel(); 
  keyPanel.setLayout(new GridLayout(4, 3)); 
  for (int i = 0; i < 12; i++) 
  { 
     JButton keyButton = new JButton(...); 
     keyPanel.add(keyButton); 
     keyButton.addActionListener(...);
  }