/// <summary>
    /// Gets an attribute from the Windows Phone App Manifest App element
    /// </summary>
    /// <param name="attributeName">the attribute name</param>
    /// <returns>the attribute value</returns>
    private static string GetAppAttribute(string attributeName)
    {
        string appManifestName = "WMAppManifest.xml";
        string appNodeName = "App";

        var settings = new XmlReaderSettings();
        settings.XmlResolver = new XmlXapResolver();

        using (XmlReader rdr = XmlReader.Create(appManifestName,settings))
        {
            rdr.ReadToDescendant(appNodeName);
            if (!rdr.IsStartElement())
            {
                throw new System.FormatException(appManifestName + " is missing " + appNodeName);
            }

            return rdr.GetAttribute(attributeName);
        }
    }