image1 = new Image();
image1.src = "/images/home_on.gif";
image2 = new Image();
image2.src = "/images/books_on.gif";
image3 = new Image();
image3.src = "/images/applications_on.gif";
image4 = new Image();
image4.src = "/images/photos_on.gif";
image5 = new Image();
image5.src = "/images/links_on.gif";