if (document.images) {

    // "on" image
    kbdpicOn = new Image();
    kbdpicOn.src = "images/bayliss_accountants_coventry_2_130x109.jpeg";

    // "off" image
    kbdpicOff = new Image();
    kbdpicOff.src = "images/bayliss_accountants_coventry_1_130x109.jpeg";

}

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

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