private void LogonOk()
        {
            // flip back - we're not on the right thread...
            this.Dispatcher.BeginInvoke(delegate()
            {
                // save...
                if (this.checkRememberMe.IsChecked.Value)
                {
                    SimpleXmlPropertyBag settings = SixBookmarksRuntime.Current.Settings;
                    settings[UsernameKey]         = this.textUsername.Text.Trim();
                    settings[PasswordKey]         = this.textPassword.Password.Trim();
                    settings.Save();
                }
                else
                {
                    this.ClearCredentials();
                }

                // do sync will come here...
                Sync sync = new Sync();
                sync.DoSync(delegate() {
                    // we worked...
                    Dispatcher.BeginInvoke(delegate()
                    {
                        NavigationService.Navigate(new Uri("/NavigatorPage.xaml", UriKind.RelativeOrAbsolute));
                    });
                }, Alert.GetFailedHandler(this));
            });
        }
        private void ClearCredentials()
        {
            // set...
            SimpleXmlPropertyBag settings = SixBookmarksRuntime.Current.Settings;

            if (settings.ContainsKey(UsernameKey))
            {
                settings.Remove(UsernameKey);
            }
            if (settings.ContainsKey(PasswordKey))
            {
                settings.Remove(PasswordKey);
            }

            // save...
            settings.Save();
        }