function preloadImages() {
   if (document.images) {
      for (var j=0; j<preloadImages.arguments.length; j++) {
         (new Image()).src = preloadImages.arguments[j];
      }
   }
}
preloadImages('graphics/btn_about_o.gif', 'graphics/btn_careers_o.gif', 'graphics/btn_contact_o.gif', 'graphics/btn_home_o.gif', 'graphics/btn_press_o.gif', 'graphics/btn_solutions_o.gif');