function roam_prefetch_layout_images()
{
  img1 = new Image();
  img1.src = "header_black.png";
  img1 = new Image();
  img1.src = "background_black.png";
  img1 = new Image();
  img1.src = "footer_black.png";
  img1 = new Image();
  img1.src = "header_white.png";
  img1 = new Image();
  img1.src = "background_white.png";
  img1 = new Image();
  img1.src = "footer_white.png";  
}