function simplePreload()
{
  var args = simplePreload.arguments;
  document.imageArray = new Array(args.length);
  for(var i=0; i<args.length; i++)
  {
    document.imageArray[i] = new Image;
    document.imageArray[i].src = args[i];
  }
}

simplePreload( 'images/btn_member_over.jpg','images/btn_join_over.jpg','images/btn_download_over.jpg','images/btn_tour_over.jpg','images/btn_video_over.jpg','images/btn_images_over.jpg',
'images/btn_member_over2.jpg','images/btn_join_over2.jpg','images/btn_download_over2.jpg','images/btn_tour_over2.jpg','images/btn_video_over2.jpg','images/btn_images_over2.jpg' );

//rollOvers

function switchImage(imgName, imgSrc)
{
  if (document.images)
  {
    if (imgSrc != "none")
    {
      document.images[imgName].src = imgSrc;
    }
  }
}