function preloadImages()
    {
      if (document.images)
      {
        services_e_off = new Image();
	services_e_off.src = "../images/services_e_off.gif";
	services_e_on = new Image();
	services_e_on.src = "../images/services_e_on.gif";

        services_p_off = new Image();
	services_p_off.src = "../images/services_p_off.gif";
	services_p_on = new Image();
	services_p_on.src = "../images/services_p_on.gif";

      }
    }
    function switchImage(name,image)
    {
      if (document.images){
	      document[name].src = image.src;
      }
    }