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

public class ExQuit extends Frame
{
    Button quitButton;

    public ExQuit()
    {
        quitButton = new Button("Click me to quit!");
        add(quitButton);
        QuitListener listener = new QuitListener();
        quitButton.addActionListener(listener);
        addWindowListener(listener);
        pack();
    }

    class QuitListener extends WindowAdapter implements ActionListener
    {
       public void actionPerformed(ActionEvent e) {  System.exit(0);  }
       public void windowClosing(WindowEvent e) {  System.exit(0);  }
    }

    public static void main(String[] args)
    {
        ExQuit app = new ExQuit();
        app.setVisible(true);
    }
}