var img_name = new Array("/images/artwork/05-10-2542.jpg", "/images/artwork/05-10-2039.jpg", "/images/artwork/07-07-2182.jpg", "/images/artwork/07-01-1221.jpg", "/images/artwork/07-08-0122.jpg", "/images/artwork/06-09-1287.jpg", "/images/artwork/06-07-1201.jpg", "/images/artwork/06-07-0332.jpg", "/images/artwork/05-10-1611.jpg", "/images/artwork/06-10-1430.jpg", "/images/artwork/07-07-2415.jpg", "/images/artwork/07-11-0029.jpg", "/images/artwork/07-08-0766.jpg", "/images/artwork/07-07-2188.jpg", "/images/artwork/06-10-1484.jpg", "/images/artwork/06-07-0969.jpg", "/images/artwork/06-07-0898.jpg", "/images/artwork/07-07-2166.jpg", "/images/artwork/07-07-2247.jpg", "/images/artwork/07-04-1644.jpg", "/images/artwork/06-10-1389.jpg", "/images/artwork/07-03-0824.jpg", "/images/artwork/07-08-1753.jpg", "/images/artwork/06-07-0866.jpg", "/images/artwork/05-10-2002.jpg", "/images/artwork/07-07-2939.jpg", "/images/artwork/05-10-1842.jpg", "/images/artwork/07-04-1669.jpg", "/images/artwork/05-10-2597.jpg", "/images/artwork/05-08-3586.jpg", "/images/artwork/07-07-2338.jpg", "/images/artwork/06-07-1360.jpg", "/images/artwork/05-10-1904.jpg", "/images/artwork/07-07-0934.jpg", "/images/artwork/07-11-0036.jpg", "/images/artwork/07-07-1745.jpg", "/images/artwork/05-10-0379.jpg", "/images/artwork/07-03-0599.jpg", "/images/artwork/05-08-3593.jpg", "/images/artwork/07-08-2009.jpg");

function set_artwork_image() {
  var l = img_name.length;
  var rnd_no = Math.floor(l*Math.random());
  document.artwork.src = img_name[rnd_no];
}