void BookmarkRemoved(object sender, BookmarkEventArgs e)
 {
     Bookmarks.SDBookmark b = e.Bookmark as Bookmarks.SDBookmark;
     if (b != null)
     {
         Bookmarks.BookmarkManager.RemoveMark(b);
     }
 }
 void BookmarkLineCountChanged(object sender, LineCountChangeEventArgs e)
 {
     foreach (Bookmark b in Document.BookmarkManager.Marks)
     {
         if (b.LineNumber >= e.LineStart)
         {
             Bookmarks.SDBookmark sdb = b as Bookmarks.SDBookmark;
             if (sdb != null)
             {
                 sdb.RaiseLineNumberChanged();
             }
         }
     }
 }