if (document.images) {
  image0 = new Image;
  image1 = new Image;
  image2 = new Image;
  image3 = new Image;
  image4 = new Image;
  image0.src = 'image_01_a.jpg';
  image1.src = 'image_02_a.jpg';
  image2.src = 'image_03_a.jpg';
  image3.src = 'image_04_a.jpg';
  image4.src = 'image_05_a.jpg';
} else {
  image0 = '';
  image1 = '';
  image2 = '';
  image3 = '';
  image4 = '';
  document.rollimg = '';
}