Applet focus problem, I think

I have an applet that requests data from the user in a JTextArea, with two buttons: OK and Cancel. It works fine--except if I enter text in the JTextArea, then move to some other part of the page containing the applet. From then on, if I try to move back to the JTextArea in the applet, everything is frozen. The buttons do not respond; I can't enter anything in the JTextArea; I can't close the browser. All I can do is use Task Manager to kill the Java Console. Then I can close the browser.

My guess is that having lost focus, the applet does not know what to do when I move the mouse back into the part of the web page that contains the applet. As a debugging thing, I added "implements WindowListener" to the applet's definition, and put in methods to log the various window events, in the hopes that this might give me some clues. But it does not appear that any of these methods are being invoked. (Perhaps there is something equivalent to WindowListener for an Applet that I should be using?)

import javax.swing.*;
import javax.swing.text.BadLocationException;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;

/**
 * This applet provides support for freeform text field inputs that can be done entirely on the 
 * GUI side.  There are currently two methods that you can call here from std_lib.js: inputTextBox, 
 * and editableTextBox.  The former is for when you want the user to enter an input string; the 
 * latter is for when you have a block of text that you want the user to be able to edit.  For both, 
 * the OK and Cancel buttons control whether the string is returned to the caller or an empty string.
 * @author ccramer
 *
 */
public class textboxApplet extends JApplet implements ActionListener, WindowListener {
	private static final long serialVersionUID = 1;
	boolean buttonPressed = false;
	boolean okay = false;

/**
	 * Constructor of the applet.
	 *
	 * @exception HeadlessException if GraphicsEnvironment.isHeadless()
	 * returns true.
	 */
	public textboxApplet() {
		super();
		System.out.println("constructor called");
	}

/**
	 * Called by the browser or applet viewer to inform
	 * this applet that it is being reclaimed and that it should destroy
	 * any resources that it has allocated. The <code>stop</code> method
	 * will always be called before <code>destroy</code>. 
	 *
	 * A subclass of <code>Applet</code> should override this method if
	 * it has any operation that it wants to perform before it is
	 * destroyed. For example, an applet with threads would use the
	 * <code>init</code> method to create the threads and the
	 * <code>destroy</code> method to kill them. 
	 */
	public void destroy() {
		System.out.println("destroy entered");
		buttonPressed = false;
		okay = false;
	}

/**
	 * Returns information about this applet. An applet should override
	 * this method to return a <code>String</code> containing information
	 * about the author, version, and copyright of the applet. 
	 *
	 * @return a string containing information about the author, version, and
	 * copyright of the applet.
	 */
	public String getAppletInfo() {
		return "This is my default applet created by Eclipse";
	}
	
	/**
	 * Called by the browser or applet viewer to inform
	 * this applet that it has been loaded into the system. It is always
	 * called before the first time that the <code>start</code> method is
	 * called. 
	 *
	 * A subclass of <code>Applet</code> should override this method if
	 * it has initialization to perform. For example, an applet with
	 * threads would use the <code>init</code> method to create the
	 * threads and the <code>destroy</code> method to kill them. 
	 */
	public void init() {
		System.out.println("entering init");
		buttonPressed = false;
		try
		{
			SwingUtilities.invokeAndWait(new Runnable() 
			{
				public void run()
				{
					//add(new JLabel("hello CIS"));
				}
			});
		}
		catch (Exception e)
		{
			System.err.println("textBoxGUI didn't complete successfully");
		}
	}
	
	public void windowClosing(WindowEvent e) {
		System.out.println("WindowListener method called: windowClosing");
	}
	
	public void windowClosed(WindowEvent e) {
 //This will only be seen on standard output.
 	System.out.println("WindowListener method called: windowClosed.");
 }
 
 public void windowOpened(WindowEvent e) {
 	System.out.println("WindowListener method called: windowOpened.");
 }
 
 public void windowIconified(WindowEvent e) {
 	System.out.println("WindowListener method called: windowIconified.");
 }
 
 public void windowDeiconified(WindowEvent e) {
 	System.out.println("WindowListener method called: windowDeiconified.");
 }
 
 public void windowGainedFocus(WindowEvent e)
	{
		System.out.println("textboxApplet window gained focus");
	}
	
	public void windowLostFocus(WindowEvent e)
	{
		System.out.println("textboxApplet window lost focus");
	}
	
	public void windowActivated(WindowEvent e)
	{
		System.out.println("textboxApplet window activated");
	}
	
	public void windowDeactivated(WindowEvent e)
	{
		System.out.println("textboxApplet window deactivated");
	}
	
	/**
	 * Called by the browser or applet viewer to inform
	 * this applet that it should start its execution. It is called after
	 * the <code>init</code> method and each time the applet is revisited
	 * in a Web page. 
	 *
	 * A subclass of <code>Applet</code> should override this method if
	 * it has any operation that it wants to perform each time the Web
	 * page containing it is visited. For example, an applet with
	 * animation might want to use the <code>start</code> method to
	 * resume animation, and the <code>stop</code> method to suspend the
	 * animation. 
	 */
	public void start() {
		System.out.println("textboxApplet start entered");
		}
	
	/**
	 * Replaces the Javascript prompt function. It displays text in a text box, OK and Cancel buttons, 
	 * and returns a String if the user hits OK. 
	 * @param msg: 	the prompt to the user
	 * @return:		String
	 * @throws InterruptedException 
	 * @throws BadLocationException 
	 */
	 public String editableTextBox(String prompt, String defaultText, int rows, int columns) throws InterruptedException, BadLocationException {
		 this.setVisible(true);
		 JPanel p = new JPanel();
		 p.setLayout(new BoxLayout(p, BoxLayout.PAGE_AXIS));
		 add(p);
		 JLabel promptMsg = new JLabel(prompt);
		 p.add(promptMsg);
		 JTextArea textBlock = new JTextArea(rows, columns);
		 textBlock.setText(defaultText);
		 textBlock.setBorder(BorderFactory.createLineBorder(Color.black));
		 textBlock.setLineWrap(true);
		 textBlock.setWrapStyleWord(true);
		 JScrollPane scrollPane = new JScrollPane(textBlock);
		 scrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED);
		 textBlock.setEditable(true);
		 p.add(scrollPane);
		 JPanel buttons = new JPanel();
		 p.add(buttons);
		 addButton(buttons, "OK");
		 addButton(buttons, "Cancel");
		 setVisible(true);
		 validate();
		 while (!buttonPressed)
			 Thread.sleep(50);
		 return (okay ? textBlock.getText() : "");
 	}

/**
	 * Replaces the Javascript prompt function.  It puts up an empty text box, OK and Cancel buttons, 
	 * and returns a String if the user hits OK.  
	 * @param msg: 	the prompt to the user
	 * @return:		String
	 * @throws InterruptedException 
	 * @throws BadLocationException 
	 */
	  public String inputTextBox(String prompt, int rows, int columns) throws InterruptedException, BadLocationException {
		  this.setVisible(true);
		  JPanel p = new JPanel();
		  p.setLayout(new BoxLayout(p, BoxLayout.PAGE_AXIS));
		  add(p);
		  JLabel promptMsg = new JLabel(prompt);
		  p.add(promptMsg);
		  JTextArea textBlock = new JTextArea(rows, columns);
		  textBlock.setText("");
		  textBlock.setBorder(BorderFactory.createLineBorder(Color.black));
		  textBlock.setLineWrap(true);
		  textBlock.setWrapStyleWord(true);
		  JScrollPane scrollPane = new JScrollPane(textBlock);
		  scrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED);
		  textBlock.setEditable(true);
		  p.add(scrollPane);
		  JPanel buttons = new JPanel();
		  p.add(buttons);
		  addButton(buttons, "OK");
		  addButton(buttons, "Cancel");
		  setVisible(true);
		  validate();
		  while (!buttonPressed)
			  Thread.sleep(50);
		  return (okay ? textBlock.getText() : "");
    	}

private void addButton(Container c, String s)
	 {
		 JButton b = new JButton(s);
		 c.add(b);
		 b.addActionListener(this);
	 }
	 
	/**
	 * Called by the browser or applet viewer to inform
	 * this applet that it should stop its execution. It is called when
	 * the Web page that contains this applet has been replaced by
	 * another page, and also just before the applet is to be destroyed. 
	 *
	 * A subclass of <code>Applet</code> should override this method if
	 * it has any operation that it wants to perform each time the Web
	 * page containing it is no longer visible. For example, an applet
	 * with animation might want to use the <code>start</code> method to
	 * resume animation, and the <code>stop</code> method to suspend the
	 * animation. 
	 */
	public void stop() {
		System.out.println("textboxApplet stop entered");
		buttonPressed = false;
		okay = false;
	}

public void actionPerformed(ActionEvent e) {
		String s = e.getActionCommand();
		buttonPressed = true;
		okay = s.equals("OK");
	}
    
}