System.Transactions.TransactionOptions op = new System.Transactions.TransactionOptions();
            op.IsolationLevel = System.Transactions.IsolationLevel.Serializable;
            op.Timeout = TimeSpan.Parse("00:01:00");
            System.Transactions.CommittableTransaction ctx = new System.Transactions.CommittableTransaction(op);

            this.наличиеTA.Connection.Open();
            this.наличиеTA.Connection.EnlistTransaction(ctx);

            this.продажиTA.Connection.Open();
            this.продажиTA.Connection.EnlistTransaction(ctx);

            try
            {
                this.наличиеTA.Update(this.DS1.Наличие);
                this.продажиTA.Update(this.DS1.Продажи);

                ctx.Commit();

                this.DS1.Продажи.Clear();
            }

            catch (Exception ex)
            {
                ctx.Rollback();

                this.DS1.Наличие.RejectChanges();
                this.DS1.Продажи.RejectChanges();

                MessageBox.Show(ex.Message);
            }

            finally
            {
                this.наличиеTA.Connection.Close();
                this.продажиTA.Connection.Close();

                ctx.Dispose();
            }