img0 = new Image(); img0.src = "images/spacer.gif";
img1 = new Image(); img1.src = "images/img1.jpg";
img2 = new Image(); img2.src = "images/img2.jpg";
img3 = new Image(); img3.src = "images/img3.jpg";
img4 = new Image(); img4.src = "images/img4.jpg";
img5 = new Image(); img5.src = "images/img5.jpg";
img6 = new Image(); img6.src = "images/img6.jpg";
img7 = new Image(); img7.src = "images/img7.jpg";
img8 = new Image(); img8.src = "images/img8.jpg";

// Function to 'activate' images.
function imgOn(imgName) {
           document["holder"].src = eval(imgName + ".src");
}

// Function to 'deactivate' images.
function imgOff(imgName) {
            document["holder"].src = eval("img0.src");
}