string sql = "update Category set Name ='"+ TextBox2.Text+"' where ID like N'" + Int32.Parse(ListBox1.SelectedValue.ToString()) + "'";
                            SqlConnection con = new SqlConnection(connectionString);
                            SqlCommand command = new SqlCommand(sql, con);
                            SqlDataAdapter adapter = new SqlDataAdapter(command);
                            DataTable table = new DataTable();
                            adapter.Fill(table);
                            Response.Redirect(Request.RawUrl);