function lightup(imgName)
 {
   if (document.images)
    {
			picOn = new Image(68,35);
			picOn.src = "images/menu_" + imgName + "_visited.jpg";
			img = eval("picOn.src");
      document[imgName].src= img;
    }
 }

function turnoff(imgName)
 {
   if (document.images)
    {
			picOff = new Image(68,35);
			picOff.src = "images/menu_" + imgName + ".jpg";

			img = eval("picOff.src");
			document[imgName].src = img;
    }
 }