function gbOpenUrl(caption, url) {
    window.document["pano"].style.visibility = 'hidden';

    var options = {
        caption: caption,
        fullscreen: true,
        callback_fn: function() {
                        window.document["pano"].style.visibility = 'visible';
                        window.document["pano"].focus();
                    }
    }
    var win = new GB_Window(options);
    win.show(url);
    win.focus();
}