Dialog box in Java

Java Program which displays a dialog box on body load(Page Load).

import java.awt.*;
import java.awt.event.*;


public class msgDialog extends Frame
{
  msgDialog()
  {
    messageBox mb = new messageBox(this,"This is a Simple Dialog Box!!!");
    mb.setLocation(200,200);
    mb.setVisible(true);
  }
 
  public static void main(String args[])
  {
    msgDialog md = new msgDialog();
    System.out.println("Displaying Dialog Box....");
    md.setVisible(true);
  }
}