if(document.images) {

    x01on = new Image();
    x01on.src = "images1/m11.jpg";
    x02on = new Image();
    x02on.src = "images1/m12.jpg";
    x03on = new Image();
    x03on.src = "images/m13.jpg";
    x04on = new Image();
    x04on.src = "images/m14.jpg";
    x05on = new Image();
    x05on.src = "images1/m15.jpg";

    x01off = new Image();
    x01off.src = "images1/m01.jpg";
    x02off = new Image();
    x02off.src = "images1/m02.jpg";
    x03off = new Image();
    x03off.src = "images/m03.jpg";
    x04off = new Image();
    x04off.src = "images/m04.jpg";
    x05off = new Image();
    x05off.src = "images1/m05.jpg";
}

function ImageOn(imgName)
{if (document.images) {imgOn = eval(imgName + "on.src");
        document.images[imgName].src = imgOn}}

function ImageOff(imgName)
{if (document.images) {imgOff = eval(imgName + "off.src");
        document.images[imgName].src = imgOff}}