var abon=new Image();
abon.src="/images/top/top_menu01.gif";

var aboff=new Image();
aboff.src="/images/top/top_menu00.gif";

var acon=new Image();
acon.src="/images/top/top_menu11.gif";

var acoff=new Image();
acoff.src="/images/top/top_menu10.gif";

var adon=new Image();
adon.src="/images/top/top_menu21.gif";

var adoff=new Image();
adoff.src="/images/top/top_menu20.gif";

var aeon=new Image();
aeon.src="/images/top/top_menu31.gif";

var aeoff=new Image();
aeoff.src="/images/top/top_menu30.gif";


function swapon(imgna){

   if(document.images)
   document[imgna].src=eval(imgna+'on.src');
   
      }

function swapoff(imgna){
   if(document.images)
   document[imgna].src=eval(imgna+'off.src');
      }