var Button1=false;
bild1=new Image(); 
bild1.src="images/lico_motorsport_auto_top.jpg"; 
bild1on=new Image();
bild1on.src="images/car2.gif";

function pictureon(name){ document[name].src=eval(name+"on.src"); } 
function pictureoff(name) { document[name].src=eval(name+".src"); } Button1=true; 
function on(name){
if (Button1) pictureon(name); } 
function off(name){ 
if (Button1) pictureoff(name); }