if(document.images) {
  tri_on = new Image();
  tri_on.src = "gif/btn_tri_on.gif";
  tri_off = new Image();
  tri_off.src = "gif/btn_tri_off.gif";
  flash_on = new Image();
  flash_on.src = "gif/btn_flash_on.gif";
  flash_off = new Image();
  flash_off.src = "gif/btn_flash_off.gif";
  pdrop_off = new Image();
  pdrop_off.src = "gif/btn_pdrop_off.gif";
  pdrop_on = new Image();
  pdrop_on.src = "gif/btn_pdrop_on.gif";
  comphp_off = new Image();
  comphp_off.src = "gif/btn_comphp_off.gif";
  comphp_on = new Image();
  comphp_on.src = "gif/btn_comphp_on.gif";
  hydrate_off = new Image();
  hydrate_off.src = "gif/btn_hydrate_off.gif";
  hydrate_on = new Image();
  hydrate_on.src = "gif/btn_hydrate_on.gif";
  aqua_on = new Image();
  aqua_on.src = "gif/btn_aqua_on.gif";
  aqua_off = new Image();
  aqua_off.src = "gif/btn_aqua_off.gif";
  sample_on = new Image();
  sample_on.src = "gif/btn_sample_on.gif";
  sample_off = new Image();
  sample_off.src = "gif/btn_sample_off.gif";
  pricing_on = new Image();
  pricing_on.src = "gif/btn_pricing_on.gif";
  pricing_off = new Image();
  pricing_off.src = "gif/btn_pricing_off.gif";
	download_on = new Image();
  download_on.src = "gif/btn_download_on.gif";
	download_off = new Image();
  download_off.src = "gif/btn_download_off.gif";
	order_on = new Image();
  order_on.src = "gif/btn_order_on.gif";
	order_off = new Image();
  order_off.src = "gif/btn_order_off.gif";
	about_on = new Image();
  about_on.src = "gif/btn_about_on.gif";
	about_off = new Image();
  about_off.src = "gif/btn_about_off.gif";
	contact_on = new Image();
  contact_on.src = "gif/btn_contact_on.gif";
	contact_off = new Image();
  contact_off.src = "gif/btn_contact_off.gif";
}