if( document.images )
{
<!--On & Off-->
  but1 = new Image(166,36) ;
  but1.src = "pics/menu/home_on.gif";
  but2 = new Image(166,36) ;
  but2.src = "pics/menu/about_on.gif";
  but3 = new Image(166,36) ;
  but3.src = "pics/menu/books_on.gif";
  but4 = new Image(166,36) ;
  but4.src = "pics/menu/distributors_on.gif";
  but5 = new Image(166,36) ;
  but5.src = "pics/menu/links_on.gif";
  but6 = new Image(166,36) ;
  but6.src = "pics/menu/contact_on.gif";
  but7 = new Image(166,25) ;
  but7.src = "pics/menu/classic_on.gif";
  but8 = new Image(166,25) ;
  but8.src = "pics/menu/bootcamp_on.gif";
  but9 = new Image(166,25) ;
  but9.src = "pics/menu/praxis_on.gif";
  but21 = new Image(166,36) ;
  but21.src = "pics/menu/home_off.gif";
  but22 = new Image(166,36) ;
  but22.src = "pics/menu/about_off.gif";
  but32 = new Image(166,36) ;
  but32.src = "pics/menu/books_off.gif";
  but42 = new Image(166,36) ;
  but42.src = "pics/menu/distributors_off.gif";
  but52 = new Image(166,36) ;
  but52.src = "pics/menu/links_off.gif";
  but62 = new Image(166,36) ;
  but62.src = "pics/menu/contact_off.gif";
  but72 = new Image(166,25) ;
  but72.src = "pics/menu/classic_off.gif";
  but82 = new Image(166,25) ;
  but82.src = "pics/menu/bootcamp_off.gif";
  but92 = new Image(166,25) ;
  but92.src = "pics/menu/praxis_off.gif";
<!--Add additional sets as needed-->
}