private void butToggleBookmark_Click(object sender, EventArgs e)
{
start2.SetBookmark(lastToggleBookmark);
lastToggleBookmark = !lastToggleBookmark;
}
private void butToogleBookmark_Click(object sender, RoutedEventArgs e)
{
_start2.SetBookmark(_lastToggleBookmark);
_lastToggleBookmark = !_lastToggleBookmark;
}