function LoginWindow(theURL,larg,alt) {
  posx=(screen.width-larg)/2;
  posy=(screen.height-alt)/2;
  features="toolbar=no,status=no,scrollbars=no,resizable=no,width=";
  features=features+larg+",height="+alt+",left="+posx+",top="+posy;
  window.open(theURL,'',features);
}

function chiudi(){
  close();
}