new Traffic

import java.applet.*;
import java.awt.*;
import java.awt.event.*;
/*<applet code="Signals" width=400 height=250></applet>*/
public class Signals extends Applet implements ItemListener
{
            String msg="";
            Checkbox  stop,ready,go;
            CheckboxGroup cbg;
            public void init()
            {
                        cbg = new CheckboxGroup();
                        stop = new Checkbox("Stop", cbg, false);
                        ready = new Checkbox("Ready", cbg, false);
                        go= new Checkbox("Go", cbg, false);
                        add(stop);
                        add(ready);
                        add(go);
                        stop.addItemListener(this);
                        ready.addItemListener(this);
                        go.addItemListener(this);

            }

            public void itemStateChanged(ItemEvent ie)
            {
                        repaint();
            }

            public void paint(Graphics g)
            {

                        msg=cbg.getSelectedCheckbox().getLabel();
                        g.drawOval(165,40,50,50);
                        g.drawOval(165,100,50,50);
                        g.drawOval(165,160,50,50);



                        if(msg.equals("Stop"))
                        {
                                    g.setColor(Color.red);
                                    g.fillOval(165,40,50,50);
                        }
                        else if(msg.equals("Ready"))
                        {
                                    g.setColor(Color.yellow);
                                    g.fillOval(165,100,50,50);
                        }
                        else
                        {
                                    g.setColor(Color.green);
                                    g.fillOval(165,160,50,50);
                        }

            }
}