if(document.images)
     {
       ccover = new Image;
       ccout  = new Image;
       ccover.src = "img/redbut1.gif";
       ccout.src  = "img/bluebut1.gif";
     }

   function ccOn(img) {
      if (document.images) document.images[img].src=ccover.src;
     }
	
   function ccOff(img) {
      if (document.images) document.images[img].src=ccout.src;
     }