dismiss modal JDialog

[jpenguin]

I am coding a reversi game as a java applet. I am using modal dialogs to inform the user if they beet the computer. I can close the dialog by the window decorations 'close', I want to hide the decoration and have my own close button-

import java.applet.*;
import java.lang.*;
import javax.swing.*;
import java.awt.*;
import java.net.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

    private Frame findParentFrame(){ 
        Container c = this; 
        while(c != null){ 
              if (c instanceof Frame) 
                return (Frame)c; 
 
          c = c.getParent(); 
        } 
    return (Frame)null; 
  } 

public void endGame(){
        Frame f = findParentFrame(); 
        final JDialog dialog = new JDialog(f, "Game Over", true);
            JButton close = new JButton("Play Again");
        if (counter_black > counter_white) {
            dialog.setLayout(new GridLayout(2, 1));
            dialog.add( new Label("You\nWon!") );
            dialog.add( close );
            dialog.pack();
        } else if (counter_black < counter_white) {
            dialog.setLayout(new GridLayout(2, 1));
            dialog.add( new Label("You\nLost!") );
            dialog.add( close );
            dialog.pack();
        } else {
            dialog.setLayout(new GridLayout(2, 1));
            dialog.add( new Label("Draw!") );
            dialog.add( close );
            dialog.pack();
        } dialog.setLocationRelativeTo(null);
        dialog.setVisible(true);
        repaint();
        close.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                dialog.setVisible(false);            }
        });
       }

The dialog displays correctly, but doesn't close with the button

[jpenguin]

    public void endGame(){
        Frame f = findParentFrame(); 
        final JDialog dialog = new JDialog(f, "Game Over", true);
            JButton close = new JButton("Play Again");
        if (counter_black > counter_white) {
            dialog.setLayout(new GridLayout(2, 1));
            dialog.add( new Label("You\nWon!") );
            dialog.add( close );
            //dialog.pack();
        } else if (counter_black < counter_white) {
            dialog.setLayout(new GridLayout(2, 1));
            dialog.add( new Label("You\nLost!") );
            dialog.add( close );
            //dialog.pack();
        } else {
            dialog.setLayout(new GridLayout(2, 1));
            dialog.add( new Label("Draw!") );
            dialog.add( close );
            //dialog.pack();
        } dialog.setLocationRelativeTo(null);
        close.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            dialog.dispose();            }
        });
        dialog.pack();
        dialog.setVisible(true);
        repaint();
 
       }