Layout Doesn't Work (was: jLabel setVisible(true) Doesn't Work)

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

@SuppressWarnings("serial")
public class Scratch extends JPanel implements ActionListener {

   private JButton vButton, iButton;
   private JLabel label;

   public Scratch() {

     vButton = new JButton("Visible");
     vButton.setMnemonic(KeyEvent.VK_D);
     vButton.setToolTipText("Sets Label visible (true)");
     vButton.setActionCommand("visible");
     vButton.addActionListener(this);
     vButton.setEnabled(false);

     iButton = new JButton("Invisible");
     iButton.setMnemonic(KeyEvent.VK_E);
     iButton.setToolTipText("Sets Label visible (false)");
     iButton.setActionCommand("invisible");
     iButton.addActionListener(this);

     label = new JLabel("Scratch");

     add(vButton);
     add(label);
     add(iButton);
   }

   public void actionPerformed(ActionEvent e) {
     if ("invisible".equals(e.getActionCommand())) {
       label.setVisible(false);
       vButton.setEnabled(true);
       iButton.setEnabled(false);
     } else {
       label.setVisible(true);
       vButton.setEnabled(false);
       iButton.setEnabled(true);
     }
   }

   private static void createAndShowGUI() {

     JFrame frame = new JFrame("Scratch");
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     Scratch scratch = new Scratch();
     frame.setContentPane(scratch);
     frame.pack();
     frame.setVisible(true);
   }

   public static void main(String[] args) {
     javax.swing.SwingUtilities.invokeLater(new Runnable() {
       public void run() {
         createAndShowGUI();
       }
     });
   }
}