/*****************************************************************
   method:  run()
   purpose: Handles the determination of the next image, sets up
            the new graphics object properties and passes it back
            to the paint() method in the main program.
  *****************************************************************/
  public void run()
  {
    // If the thread is in running mode, then calculate
    // the next image to be displayed by the program
    while(running)
    {
      // First image
      if (mode == MODE_ON)
      {
        background = Toolkit.getDefaultToolkit().getImage(firstimage);
        //System.out.println("Printing player_old.gif");
        mode = MODE_OFF;
      }
      // Second image
      else
      {
        background = Toolkit.getDefaultToolkit().getImage(secondimage);
        //System.out.println("Printing player2.gif");
        mode = MODE_ON;
      }

      // Repaint the scene to clear what was there last
      mainprog.repaint();

      // Draw the new image
      g.drawImage(background, xpos, ypos, mainprog); 

      // Put the thread to sleep for the specified amount of time
      // in the sleep duration variable
      try{
        Thread.sleep(sleeptime);
      }
      catch (InterruptedException e)
      {}
    }
    
    // If we are no longer running, we want to repaint the scene
    if (!running)
    {
      mainprog.repaint();
    }
  }