function wopen(url, name, w, h)

{

  // Fudge factors for window decoration space.

  // In my tests these work well on all platforms & browsers.

  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=no, toolbar=no, scrollbars=no, resizable=no');

  // Just in case width and height are ignored

  win.resizeTo(w, h);

  // Just in case left and top are ignored

  win.moveTo(wleft, wtop);

  win.focus();

}