function zoom(img){
  zoom_pic= new Image();
  zoom_pic.src=(img);
  Controlla(img);
}
function Controlla(img){
  if((zoom_pic.width!=0)&&(zoom_pic.height!=0)){
    viewzoom_pic(img);
  }
  else{
    funzione="Controlla('"+img+"')";
    intervallo=setTimeout(funzione,20);
  }
}
function viewzoom_pic(img){
  largh=zoom_pic.width+20;
  altez=zoom_pic.height+20;
  stringa="width="+largh+",height="+altez;
  finestra=window.open(img,"",stringa);
}