private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection conn = new SqlConnection("server= .\\SQLEXPRESS;uid=testuser1;pwd=test123;database=manage");
            conn.Open();
            SqlCommand cmd = new SqlCommand();

           SqlTransaction sqltran = conn.BeginTransaction();
           cmd.Connection = conn;
           cmd.Transaction = sqltran;

            try
            {
                for (int i = 0; i < 99999; i++)
                {
                    cmd.CommandText ="UPDATE [newplan] SET [dept] = '" + i + "' WHERE [number]='11'";
                    cmd.ExecuteNonQuery();
                    txt_number.Text = i.ToString();

                }
                 sqltran.Commit();

            }
            catch
            {
               sqltran.Rollback();
            }
            finally
            {
                conn.Close();
            }