applet version of System.exit(0)

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

/**
 *  MyFirstFrame class
 *
 * <p>
 * A sample frame to illustrate the placing of GUI objects and event handling.
 */
class MyFirstFrame extends Frame implements ActionListener
{

//----------------------------------
//    Data Members
//----------------------------------
    
    /**
     * Default frame width
     */
    private static final int FRAME_WIDTH    = 300;
    
    /**
     * Default frame height
     */
    private static final int FRAME_HEIGHT   = 200;
    
    /**
     * X coordinate of the frame default origin point
     */
    private static final int FRAME_X_ORIGIN = 150;
    
    /**
     * Y coordinate of the frame default origin point
     */
    private static final int FRAME_Y_ORIGIN = 250;

    /**
     * Default width for buttons
     */
    private static final int BUTTON_WIDTH  = 60;
     
    /**
     * Default height for buttons
     */
    private static final int BUTTON_HEIGHT = 30;

    /**
     * The GUI button for Cancel
     */
    private Button cancelButton;
    
    
    /**
     * The GUI button for OK
     */
    private Button okButton;
    
   

//----------------------------------
//    Constructors
//----------------------------------
                                
    /**
     * Default constructor
     */
    public MyFirstFrame()
    {
        //set the frame properties
        setSize      (FRAME_WIDTH, FRAME_HEIGHT);
        setResizable (false);
        setTitle     ("Program MyFirstFrame");
        setLocation  (FRAME_X_ORIGIN, FRAME_Y_ORIGIN);
        setLayout    (null);
        
        //create and place two buttons on the frame
        okButton = new Button("OK");
        okButton.setBounds(100, 150, BUTTON_WIDTH, BUTTON_HEIGHT);
        add(okButton);
        
        cancelButton = new Button("CANCEL");
        cancelButton.setBounds(170, 150, BUTTON_WIDTH, BUTTON_HEIGHT);
        add(cancelButton);
  
        //register this frame as an action listener of the two buttons
        cancelButton.addActionListener(this);
        okButton.addActionListener(this);
        
        //register a ProgramTerminator object as the window listener of this frame
        addWindowListener(new ProgramTerminator());
    }
   
//-------------------------------------------------
//      Public Methods:
// 
//          void    actionPerformed   (   ActionEvent        )
//
//------------------------------------------------
                                
    /**
     * Standard method to respond the action event.
     * 
     * @param event the ActionEvent object
     *
     */
    public void actionPerformed(ActionEvent event) 
    {
        Button clickedButton = (Button) event.getSource();
        
        if (clickedButton == cancelButton) {
           setTitle("You clicked CANCEL");
        }
        else { //the event source must be okButton
           setTitle("You clicked OK");
        }
    }
   
}

/*
    ProgramTerminator Class

    A ProgramTerminator object terminates the program when its main window
    generates a window closing event.
*/

import java.awt.event.*;

class ProgramTerminator implements WindowListener
{

/******************************

    Window Event Handling

*******************************/

   public void windowClosing( WindowEvent event )
   {
      System.exit(0);
   }

   public void windowActivated   (WindowEvent event) { }
   public void windowClosed      (WindowEvent event) { }
   public void windowDeactivated (WindowEvent event) { }
   public void windowDeiconified (WindowEvent event) { }
   public void windowIconified   (WindowEvent event) { }
   public void windowOpened      (WindowEvent event) { }

}