Private Sub UpdateWithTransactions()
  Dim conn As SqlConnection = New SqlConnection
  conn.ConnectionString = "server=NOMEDBSERVER;database=NOMEDB;uid=USERID;pwd=PASSWORD;"
  conn.Open()
  Dim trans As SqlTransaction
  trans = conn.BeginTransaction()

  Try
    Dim sql1 As String = "Insert INTO Tabella1 (campo) VALUES ('valore')"
    Dim sql2 As String = "Insert INTO Tabella2 (campo1,campo2) VALUES ('valore1','valore2')"
    Dim comm As SqlCommand = New SqlCommand
    comm.Connection = conn

    'Inizia la transazione
    comm.Transaction = trans
    'prima query
    comm.CommandText = sql1
    comm.ExecuteNonQuery()
    'seconda query
    comm.CommandText = sql2
    comm.ExecuteNonQuery()

    'eseguo la transazione
    trans.Commit()
    Response.Write("Fine elaborazione")
  Catch ex As SqlException
    'se si sono verificati errori faccio il rollback
    trans.Rollback()
    Response.Write(ex.ToString())
  Finally
    'chiudiamo sempre le connessioni!
    conn.Close()
  End Try
End Sub