function right(e) {
   if (navigator.appName == 'Netscape' && (e.which == 3 || e.which == 2))
    return false;
   else if (navigator.appName == 'Microsoft Internet Explorer' && (event.button == 2 || event.button == 3)) {
    alert("Utilizzare il solo tasto sinistro del mouse");
    return false;}
   return true;
  }
  document.onmousedown=right;
  if (document.layers) window.captureEvents(Event.MOUSEDOWN);
   window.onmousedown=right;