string sql = "DELETE FROM musteribilgi where musteriNo= @musteriNo";
            cmd = new MySqlCommand(sql, con);
            cmd.Parameters.AddWithValue("@musteriNo", txtArMusteriNo.Text);
            con.Open();
            cmd.ExecuteNonQuery();
            dataGridView1.Refresh();
            dataGridView1.Update();
            mustlistele();
            con.Close();