مثال في Displaying Input Dialog Boxes

لماذا تظهر لي اخطاء مع ان الكود منقول من الانترنت

http://www.herongyang.com/Swing/JOptionPane-Display-Input-Dialog-Box.html'>http://www.herongyang.com/Swing/JOptionPane-Display-Input-Dialog-Box.html

كلما حاولت ان اتعلم ذاتيا ارى العقبات امامي تكبر

/**

* JOptionPanelInputDialog.java

* Copyright © 2009 by Dr. Herong Yang, http://www.herongyang.com/

*/

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

import javax.swing.event.*;

public class JOptionPanelInputDialog implements ActionListener {

JFrame myFrame = null;

public static void main(String[] a) {

(new JOptionPanelInputDialog()).test();

}

private void test() {

myFrame = new JFrame("showInputDialog() Test");

myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

Container myPane = myFrame.getContentPane();

JButton myButton = new JButton("Show");

myButton.addActionListener(this);

myPane.add(myButton);

myFrame.pack();

myFrame.setVisible(true);

}

public void actionPerformed(ActionEvent e) {

int messageType = JOptionPane.INFORMATION_MESSAGE;

String answer = JOptionPane.showInputDialog(myFrame,

"What's you name?",

"Input Dialog Box", messageType);

System.out.println("Answer: "+answer);

}

}