if (document.images) {

   tn_products_copy       = new Image();
   tn_products_copy.src   = "/images/products_white_copy.gif";
   tn_support_copy        = new Image();
   tn_support_copy.src    = "/images/support_white_copy.gif";
   tn_downloads_copy      = new Image();
   tn_downloads_copy.src  = "/images/downloads_white_copy.gif";
   tn_speech_copy         = new Image();
   tn_speech_copy.src     = "/images/Speech_white_copy.gif";
   tn_links_copy          = new Image();
   tn_links_copy.src      = "/images/Links_white_copy.gif";
   tn_comments_copy       = new Image();
   tn_comments_copy.src   = "/images/Comments_white_copy.gif";
   tn_freestuff_copy      = new Image();
   tn_freestuff_copy.src  = "/images/Freestuff_white_copy.gif";
   tn_dtalk_copy          = new Image();
   tn_dtalk_copy.src	  = "/images/dtalk_white_copy.gif";
   tn_combobox_copy       = new Image();
   tn_combobox_copy.src	  = "/images/combobox_white_copy.gif";
   tn_tutility_copy       = new Image();
   tn_tutility_copy.src	  = "/images/tutility_white_copy.gif";

   null_copy           = new Image();
   null_copy.src       = "/images/spacer_white.gif";
}

function tnImgOn(imgName) {
   if (document.images) {
      document[imgName].src = eval(imgName + "_on.src");
   }
}

function tnImgOff(imgName) {
   if (document.images) {
      document[imgName].src = eval(imgName + "_off.src");
   }
}

function tnCopyOn(imgName) {
   if (document.images) {
      document['copy'].src = eval(imgName + "_copy.src"); 
   }
}

function tnCopyOff(imgName) {
   if (document.images) {
      document['copy'].src = null_copy.src;
   }
}