Program to explain CardLayout in Java

//  Program to explain CardLayout.
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
/*
<applet code="CardLayoutDemo" width=300 height=100>
</applet>
*/
public class CardLayoutDemo extends Applet implements ActionListener, MouseListener 
{
Button b1, b2, b3, b4, b5;
Panel mainPanel;
CardLayout cardLO;
Button bCard1, bCard2;
public void init() 
{
 bCard1 = new Button("Card1");
 bCard2 = new Button("Card2");
 
 add(bCard1);
 add(bCard2);
 
 cardLO = new CardLayout();
 mainPanel = new Panel();
 mainPanel.setLayout(cardLO);  
 
 b1 = new Button("Button-1");
 b2 = new Button("Button-2");
 b3 = new Button("Button-3");
 b4 = new Button("Button-4");
 b5 = new Button("Button-5");

 Panel p1 = new Panel();
 p1.add(b1);
 p1.add(b2);
 p1.add(b3);
 Panel p2 = new Panel();
 p2.add(b4);
 p2.add(b5);
 mainPanel.add(p1, "Card1");
 mainPanel.add(p2, "Card2");
 add(mainPanel);
 bCard1.addActionListener(this);
 bCard2.addActionListener(this);
 addMouseListener(this);
}

public void mousePressed(MouseEvent me) 
{
 cardLO.next(mainPanel);
}

public void mouseClicked(MouseEvent me) 
{
}
public void mouseEntered(MouseEvent me) 
{
}
public void mouseExited(MouseEvent me) 
{
}
public void mouseReleased(MouseEvent me) 
{
}
public void actionPerformed(ActionEvent ae) 
{
 if(ae.getSource() == bCard1) 
 {
  cardLO.show(mainPanel, "Card1");
 }
 else 
 {
  cardLO.show(mainPanel, "Card2");
 }
}
}