if (document.images) {
  preload_image_object = new Image();
  image_url = new Array();
  image_url[0] = starOn;
  image_url[1] = starOff;
  preload_image_object.src = image_url[0];
  preload_image_object.src = image_url[1];
}
function activateStars(n) {
  for (x = 1; x < 6; x++) {
    var starElement = document.getElementById('star' + x);
    if (x > n && starElement.src != starOff) {
      starElement.src = starOff;
    }
  }
  for (x = 1; x < n+1; x++) {
    var starElement = document.getElementById('star' + x);
    if (starElement.src != starOn) {
        starElement.src = starOn;
    }
  }
}
function resetStars(n) {
  activateStars(n);
}