Code snippet to create an applet (Java)

package applet;

import java.applet.Applet;
import java.awt.Button;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class FirstApplet extends Applet implements ActionListener 
{
 Button buttonDefault,ButtonRed,ButtonBlue;
 public void init()
 {
  this.setBackground(Color.yellow);
  
  buttonDefault = new Button("Default");
  ButtonRed = new Button("Red");
  ButtonBlue = new Button("Blue");
  
  this.add(buttonDefault);
  this.add(ButtonRed);
  this.add(ButtonBlue);
  
  buttonDefault.addActionListener(this);
  ButtonRed.addActionListener(this);
  ButtonBlue.addActionListener(this);
  
 }
 public void actionPerformed(ActionEvent e)
 {
  if(e.getSource()==buttonDefault)
   this.setBackground(Color.yellow);
  else if(e.getSource()==ButtonRed)
   this.setBackground(Color.red);
  else
   this.setBackground(Color.blue);
 }

}