Sudoku.Form1.Box2_TextChanged C# (CSharp) Method

        private void Box2_TextChanged(object sender, EventArgs e)
        {
            int[,] arr = mapTableToArray();

            CCC = new CheckCorrectCell(arr);

            if (CCC.checkCorrectCell9x9(0, 1) &&

                Box2.Text != "")
            {
                Box2.BackColor = Color.Red;
            }
            else
                Box2.BackColor = Color.White;
            congratulations9x9();
        }