function mouseOverPic(a) {
   	 var n = "img/start_"+a+"_grosso.jpg";
   	 document.getElementById(a).setAttribute("src", n);
   }
 
   function mouseOutPic(a) {
   	 var n = "img/start_"+a+"_kleino.jpg";
   	 document.getElementById(a).setAttribute("src", n);
   }