function rollover(imgDocID, imgObjName, imgLayerID) {
  if (imgLayerID) {
     if (isNav4 || isNav6) {
       if (isNav4) {
          document.eval(imgLayerID).document.images[imgDocID].src = eval(imgObjName + ".src");
       }
       else {
          theObj = document.getElementById(imgDocID);
          theObj.setAttribute("src", eval(imgObjName + ".src"));
       }
     }
     else {
       document.all[imgLayerID].document.images[imgDocID].src = eval(imgObjName + ".src");
     }
  }
  else {
    document.images[imgDocID].src = eval(imgObjName + ".src");
  }
}