img_G0 = new Image ();
img_G0.src = "Half-L-3.gif";
img_G1 = new Image ();
img_G1.src = "Half-L-4.gif";
img_G2 = new Image ();
img_G2.src = "Half-R-3.gif";
img_G3 = new Image ();
img_G3.src = "Half-R-4.gif";

function switch_image_logo (img_nr, img_obj)
 {window.document.images[img_nr].src = img_obj.src;}

function switch_image (img_id, img_obj)
 {var img = get_element (img_id);
  img.src = img_obj.src;}