sudoku.draw() method update

PuzzlePlayer/Sudoku.cs

@@ -69,6 +69,19 @@ namespace PuzzlePlayer_Namespace
                     }
                 }
             }
+            for (int i = 1; i < Math.Sqrt(boardState.GetLength(0)); i++)
+            {
+                gr.DrawLine(Pens.Black,
+                    r.X + i * (int)Math.Sqrt((double)boardState.GetLength(0)) * tilesize.Width,
+                    r.Y,
+                    r.X + i * (int)Math.Sqrt((double)boardState.GetLength(0)) * tilesize.Width,
+                    r.Bottom);
+                gr.DrawLine(Pens.Black,
+                    r.X,
+                    r.Y + i * (int)Math.Sqrt((double)boardState.GetLength(1)) * tilesize.Height,
+                    r.Right,
+                    r.Y + i * (int)Math.Sqrt((double)boardState.GetLength(1)) * tilesize.Height);
+            }
         }
 
         public override void Generate()