// preload images for rollovers

   if (document.images) 
   {
      menudir = "http://www.kera.org/images/artandseek/nav/";

      modeSearch1 = new Image(116,19);
      modeSearch1.src = menudir + "modeSearch1.gif";
      modeSearch2 = new Image(116,19);
      modeSearch2.src = menudir + "modeSearch2.gif";

      modeFeatures1 = new Image(71,19);
      modeFeatures1.src = menudir + "modeFeatures1.gif";
      modeFeatures2 = new Image(71,19);
      modeFeatures2.src = menudir + "modeFeatures2.gif";

      modeBlog1 = new Image(73,19);
      modeBlog1.src = menudir + "modeBlog1.gif";
      modeBlog2 = new Image(73,19);
      modeBlog2.src = menudir + "modeBlog2.gif";
   }

   // simple image replacements

   function rollOn(imgID)
   {
      if (document.images) document.images[imgID].src = eval(imgID + "2.src"); 
   }

   function rollOff(imgID)
   {
      if (document.images) document.images[imgID].src = eval(imgID + "1.src"); 
   }