DIALOG BOX SHOW CODE IN SWING JAVA

import javax.swing.*;
import java.awt.event.*;
public class Dialog {
  JFrame frame;
  JPanel p;
  public Dialog(){

  frame = new JFrame("Show Message Dialog");
  p=new JPanel();
  JButton button = new JButton("Click Me");
  button.addActionListener(new MyAction());
 
  p.add(button);

  frame.add(p);
  frame.setSize(400, 400);
  frame.setVisible(true);
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  }

  public class MyAction implements ActionListener{
  public void actionPerformed(ActionEvent e){
  JOptionPane.showMessageDialog(frame,"My DialogBox");
  }

  }
 public static void main(String[] args)
 {
    Dialog db = new Dialog();
  }
}