private static void OnIsOverlayContentVisibleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        jonblind blind = d as jonblind;

        if (blind != null)
        {
            SetVisibility(blind);
        }
    }
 private static void SetVisibility(jonblind blind)
 {
     blind.blindGrid.Visibility = blind.IsContentVisible ? Visibility.Visible : Visibility.Hidden;
 }