var win = null;

function launch(winurl) {
  if (win && win.open && !win.closed) win.close();
  winfeatures = 'scrollbars=yes,resizable=yes,status=no,toolbar=yes,directories=no,menubar=no,location=no,width=750,height=680,left=1,top=1';
  win = window.open(winurl,"ventana01",winfeatures);    
  return false;
}