function rollover(imgname, imgsrc)
{
  var img = document.images[imgname];
  img.oldsrc = img.src;
  img.src = imgsrc;
}

function rollout(imgname)
{
  var img = document.images[imgname];
  img.src = img.oldsrc;
}

function preloadImage(imgsrc)
{
  var img = new Image();
  img.src = imgsrc;
}

preloadImage("/images/news-over.gif");
preloadImage("/images/biography-over.gif");
preloadImage("/images/releases-over.gif");
preloadImage("/images/events-over.gif");
preloadImage("/images/services-over.gif");
preloadImage("/images/voices-over.gif");
preloadImage("/images/info-over.gif");