if (document.images) {
homeOn = new Image();
homeOn.src = "images/nav_home_mouse.gif";
homeOff = new Image();
homeOff.src = "images/nav_home.gif";

aboutOn = new Image();
aboutOn.src = "images/nav_about_mouse.gif";
aboutOff = new Image();
aboutOff.src = "images/nav_about.gif";

photosOn = new Image();
photosOn.src = "images/nav_photos_mouse.gif";
photosOff = new Image();
photosOff.src = "images/nav_photos.gif";

systemsOn = new Image();
systemsOn.src = "images/nav_systems_mouse.gif";
systemsOff = new Image();
systemsOff.src = "images/nav_systems.gif";

contactOn = new Image();
contactOn.src = "images/nav_contact_mouse.gif";
contactOff = new Image();
contactOff.src = "images/nav_contact.gif";

photo_exteriorOn = new Image();
photo_exteriorOn.src = "images/nav_photo_exterior_mouse.gif";
photo_exteriorOff = new Image();
photo_exteriorOff.src = "images/nav_photo_exterior.gif";

photo_interiorOn = new Image();
photo_interiorOn.src = "images/nav_photo_interior_mouse.gif";
photo_interiorOff = new Image();
photo_interiorOff.src = "images/nav_photo_interior.gif";

photo_groundsOn = new Image();
photo_groundsOn.src = "images/nav_photo_grounds_mouse.gif";
photo_groundsOff = new Image();
photo_groundsOff.src = "images/nav_photo_grounds.gif";
}

function activate(image_name) {
if (document.images) {
document[image_name].src = eval(image_name + "On.src");
}
}
function deactivate(image_name) {
if (document.images) {
document[image_name].src = eval(image_name + "Off.src");
}
}