function tabella(file){
   var w = 650;
   var h = 500;
   var l = Math.floor((screen.width-w)/2);
   var t = Math.floor((screen.height-h)/2);
      window.open("./popup/" + file,"search","width=" + w + ",height=" + h + ",top=" + t + ",left=" + l + ",scrollbars=yes");
}