function swapin(imgName, desc) {
  if (document.images)
    document.images[imgName].src = "images/" + imgName + "-on.gif";
  window.status=desc;
  return true;
}
function swapout(imgName) {
  if (document.images)
    document.images[imgName].src = "images/" + imgName + ".gif";
  window.status='';
  return true;
}