import java.applet.*;
import java.awt.*;
import java.awt.Event.*;
public class Class3 extends Applet implements actionlistener
{
Button btn =new Button("结束");
btn.setBackground(Color.yellow);
add(btn);
btn.addActionlistener(this)
public void ActionPerformed(actionvent e )

{
if(e.getsource()==btn)
System.exit(0);
}
}