public void showAboutDialog() {
        // Added to swing thread to ensure it shows up on top of main
        // browser window
        Runnable doSwingWork = new Runnable() {
            public void run() {
                AboutDialog ad = new AboutDialog(viewer, messageBundle, true,
                        AboutDialog.OK, AboutDialog.NO_TIMER);
                ad.setVisible(true);
            }
        };
        SwingUtilities.invokeLater(doSwingWork);
    }