function wopen(url, name, w, h)
{
  w += 32;
  h += 96;
  wleft = (screen.width - w) / 2;
  wtop = (screen.height - h) / 2;
  var win = window.open(url,
    name,
    'width=' + w + ', height=' + h + ', ' +
    'left=' + wleft + ', top=' + wtop + ', ' +
    'location=no, menubar=no, ' +
    'status=yes, toolbar=no, scrollbars=yes, resizable=yes');

  win.resizeTo(w, h);
  win.moveTo(wleft, wtop);
  win.focus();
}