import java.awt.*; 
import java.awt.event.*;

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