image1 = new Image();
image1.src = "images/home.gif";
image2 = new Image();
image2.src = "images/home_h.gif";
image3 = new Image();
image3.src = "images/sitemap.gif";
image4 = new Image();
image4.src = "images/sitemap_h.gif";
image5 = new Image();
image5.src = "images/contactus.gif";
image6 = new Image();
image6.src = "images/contactus_h.gif";

function move_in(img_name,img_src) {
document[img_name].src=img_src;
}

function move_out(img_name,img_src) {
document[img_name].src=img_src;
}