//WindowDestroyer.java

import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

/**
 * If you register an object of this class as a listener to any
 * object of the class JFrame, the object will end the program
 * and close the JFrame window, if the user clicks the window's
 * close-window button.
 */
public class WindowDestroyer
    extends WindowAdapter
{
    public void windowClosing
    (
        WindowEvent e
    )
    {
        System.exit(0);
    }
}