WindowDestroyer can not pass compile

I am new to Java Graphic, Here is my code, very simple one.

import javax.swing.*;

public class SwingDemo

{

public static void main(String[] argus)

{

JFrame myWindow = new JFrame();

myWindow.setSize(300,200);

JLabel myLabel = new JLabel("hi flyingtide");

myWindow.getContentPane().add(myLabel);

myWindow.setVisible(true);

WindowDestroyer myListener = new WindowDestroyer();

myWindow.addWindowListener(myListener);

myWindow.setVisible(true);

}

}

But when compile,the error msg always point to --> WindowDestroyerand say"can not resolve sumbol" .

What hava I did wrong?

Thanks.

[697 byte] By [puputaoa] at [2007-10-1 6:43:50]