function swap_image(newsrc,element,ln) {
  document.getElementById(element).src = newsrc;
  if (typeof ln != 'undefined') {
    document.getElementById(element+'_href').href   = '/'+ln;
    document.getElementById(element+'_href').title  = 'Go to '+ln;
    document.getElementById(element).title          = 'Go to '+ln;
  }
  return false;
}