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 += 54;
    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();
}