To make a class that can run as both an applet and an application,
write your applet and then put in a main() method that looks like this:

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

public class Fred extends Applet
{
   public static void main(String [] args)
   {
      Frame i = new Frame(); // choose more meaningful names
      Fred j = new Fred();

      j.init();


      // this code makes it so your application will close the window
      i.addWindowListener(new WindowAdapter() 
	 {
            public void windowClosing(WindowEvent e) 
            {
                System.exit(0);
            } // windowClosing
         });

      i.add(j);
      i.pack();
      i.setSize(500, 600); // make it whatever size you made your applet
      i.setVisible(true);
   } // main
} // Fred