var imgs = new Array(); var imgcnt = 0; var thisimg = 0;
imgs[imgcnt++] = '1.jpg';
imgs[imgcnt++] = '2.jpg';
imgs[imgcnt++] = '3.jpg';
imgs[imgcnt++] = '4.jpg';

 
function rotate() {
if (document.images) {
  thisimg++;
  if (thisimg >= imgcnt) thisimg = 0;
  document.rollimg.src = imgs[thisimg];
  setTimeout("rotate();",5000);
}
}
setTimeout("rotate();",5000);