Create a simple swing applet that demonstrate checkbox and radio button

           import java.applet.*;

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

/*

<applet code="box" width=400 height=400>

                        </applet>

*/

public class box extends JApplet implements ItemListener

            {

                                    Container c;

                                    JLabel l1,l2;

JCheckBox c1,c2,c3;

                 JRadioButton r1,r2,r3;

                                    ButtonGroup bg;

public void init()

{

                                    c=this.getContentPane();

                                    c.setLayout(new FlowLayout());

            c1=new JCheckBox("Red");

                                     c.add(c1);

                             c2=new JCheckBox("Green");

                                     c.add(c2);

                                    c3=new JCheckBox("Blue");

                                     c.add(c3);       

                                     l1=new JLabel();

                                    c.add(l1);

c1.addItemListener(this);

                                     c2.addItemListener(this);

                                     c3.addItemListener(this);

                                     l2=new JLabel();

                                     c.add(l2);

                                     r1=new JRadioButton("Red");

                                     c.add(r1);

                                     r2=new JRadioButton("Green");

                                     c.add(r2);

                                     r3=new JRadioButton("Blue");

                                     c.add(r3);

                                     bg=new ButtonGroup();

                                     bg.add(r1);

                                     bg.add(r2);

                                     bg.add(r3);

                                    r1.addItemListener(this);

                                     r2.addItemListener(this);

                                     r3.addItemListener(this);

}

public void itemStateChanged(ItemEvent ie)

                         {

                                    if(ie.getSource()==c1)

                                    l1.setText("Red is marked");

                                    if(ie.getSource()==c2)

                                    l1.setText("Green is marked");

                                    if(ie.getSource()==c3)

                                    l1.setText("Blue is marked");

                                    if(ie.getSource()==r1)

                                    l2.setText("Red is marked");

                                    if(ie.getSource()==r2)

                                    l2.setText("Green is marked");

                                    if(ie.getSource()==r3)

                                    l2.setText("Blue is marked");

                         }

        }