帮我看看JAVA的红绿灯的程序，嘻嘻 小妹在此谢啦

[aidapang123]

package my;
import java.awt.*;
import java.awt.event.*;
public class MyFrame implements ItemListener{
Frame fr;
Canvas canvas;
Choice c1;
Component cmp;

void MyFrame(){

fr=new Frame("信号灯");
c1.add("红灯");
c1.add("绿灯");
c1.add("黄灯");
c1.addItemListener(this);
fr.add(c1,"North");

fr.setSize(500,300);
fr.setVisible(true);
}
void cmp(){
canvas=new Canvas();
cmp.add(canvas,"Center");}

}
class Canvas{

public void Paint(Graphics g){

g.drawOval(150, 50,80,80);
g.setColor(Color.red);}




public void itemStateChanged(ItemEvent e){
e.getItemSelectable();
if(e.getSource()==c1){
String color=c1.getSelecedItem();
if (color=="红灯")
{g.setColor(Color.red);}
if(color=="绿灯")
{g.setColor(Color.green);}
if(color=="黄灯")
{g.setColor(Color.yellow);}




public void windowClosing(WindowEvent e){
System.exit(1);
}
public class myGraphics{
public void main(String[] args){
new MyFrame();
}