function finestra(str) {
  w=500;
  h=400;
     t = Math.floor((screen.height-h)/2);
     l = Math.floor((screen.width-w)/2);
  stringa ="width="+ w+ ",height="+ h +",top="+ t +",left=" + l +"";
        searchWin = window.open(str,'finestra',stringa,'scrollbars=no,resizable=no,status=no,location=no,toolbar=no');

//        searchWin.refer = self;

}