if (document.images) {

			johnon = new Image();
            johnon.src = "/john_on.jpg";
			johnoff = new Image();
            johnoff.src = "/john.jpg";
			markon = new Image();
            markon.src = "/mark_on.jpg";
			markoff = new Image();
            markoff.src = "/mark.jpg";
			daveon = new Image();
            daveon.src = "/dave_on.jpg";
			daveoff = new Image();
            daveoff.src = "/dave.jpg";
			keithon = new Image();
            keithon.src = "/keith_on.jpg";
			keithoff = new Image();
            keithoff.src = "/keith.jpg";
			jimmyon = new Image();
            jimmyon.src = "/jimmy_on.jpg";
			jimmyoff = new Image();
            jimmyoff.src = "/jimmy.jpg";

			}

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

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