Problem med att uppdatera en JPanel

import java.awt.FlowLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class ExampleCode {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		new ExampleCode();
	}

	public ExampleCode() {
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				MyGUI();
			}
		});
	}
	
	private MyWindow window;;
	private MyWindow window2;
	private JFrame frame;
	
	public void MyGUI(){
		frame = new JFrame("Example application");
		frame.setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
		JPanel myPanel = new JPanel();
		JPanel myPanel2 = new JPanel();
		FlowLayout layout = new FlowLayout();
		frame.setLayout(layout);
		myPanel.setLayout(layout);
		myPanel2.setLayout(layout);
		JButton button = new JButton("Click me");
		button.addMouseListener(new MouseAdapter() {
			public void mousePressed(MouseEvent e) {
				window.setMyWindow(window2);
				window.updateUI();
				frame.repaint();
				frame.getRootPane().revalidate();
				frame.getRootPane().repaint();
				window.revalidate();
				window.getRootPane().revalidate();
			}
		});
		myPanel.add(button);
		myPanel2.add(new JLabel("Ändrat till myWindow2!"));
		window = new MyWindow(myPanel, "myWidnow");
		window2 = new MyWindow(myPanel2, "myWindow2");
		frame.add(window);
		frame.pack();
		frame.setVisible(true);
	}
}

import java.awt.BorderLayout;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class MyWindow extends JPanel{

	protected String title;
	protected JPanel lowerPanel;
	
	public MyWindow(JPanel panel, String name){
		this.title = name;
		this.lowerPanel = panel;
		initComponents();
	}
	
	public void initComponents() {
		JPanel topPanel = new JPanel();
		topPanel.add(new JLabel(title));
		BorderLayout layout = new BorderLayout();
		this.setLayout(layout);
		this.add(topPanel, BorderLayout.NORTH);
		this.add(lowerPanel, BorderLayout.CENTER);
		this.setVisible(true);
	}
	
	public String getTitle(){
		return title;
	}
	
	public void setTitle(String newTitle){
		title = newTitle;
	}
	
	public void setLowerPanel(JPanel newPanel){
		lowerPanel = newPanel;
	}
	
	public JPanel getLowerPanel(){
		return lowerPanel;
	}
	
	public void setMyWindow(MyWindow newMw){
		title = newMw.getTitle();
		lowerPanel = newMw.getLowerPanel();
		updateUI();
		lowerPanel.updateUI();
		lowerPanel.revalidate();
		revalidate();
		repaint();
		getRootPane().revalidate();
	}
}