var tmpimg = new Image();
  tmpimg.onload = displayImg;

  function updateImage() {
    ran = Math.random()
    tmpimg.src = '/smallwebcam.jpg/ran=' + ran;
    setTimeout("updateImage()", 15 * 1000);
  }

  function displayImg() {
    e = document.getElementById('webcam');
//    e.src = tmpimg.src;
    if (e) e.style.background = "url(" + tmpimg.src + ") no-repeat";
  }

  updateImage();