multiple transactions

Hi

I want to use transactions in a vb.net application. This is the working code I have so far:

       Dim sqlCommand As String = "SELECT * FROM tblMyTable"

        Dim da1 As New SqlClient.SqlDataAdapter

        da1 = New SqlClient.SqlDataAdapter(sqlCommand, objConnection)

        Dim cmdClientsBuilder As New SqlClient.SqlCommandBuilder
        cmdClientsBuilder = New SqlClient.SqlCommandBuilder(da1)
        da1.InsertCommand = cmdClientsBuilder.GetInsertCommand()
        da1.DeleteCommand = cmdClientsBuilder.GetDeleteCommand()
        da1.UpdateCommand = cmdClientsBuilder.GetUpdateCommand()

        Dim txn As SqlClient.SqlTransaction = objConnection.BeginTransaction

        da1.UpdateCommand.Transaction = txn
        da1.DeleteCommand.Transaction = txn
        da1.InsertCommand.Transaction = txn

        Try
            da1.Update(Me.dt1)
            txn.Commit()
            Console.WriteLine("Insert succeeded")
        Catch ex As Exception
            txn.Rollback()
            MessageBox.Show(ex.Message)
            Console.WriteLine("Insert Failed")
        Finally
            'Optional. A Finally block is always executed when execution leaves any part of the Try statement.
        End Try

HOWEVER, I am puzzled how to use this if I had another update which I wanted to perform. For example, suppose I wanted to update another table as well e.g. dt2

        Try
            da1.Update(Me.dt1)
            da2.Update(Me.dt2)
            txn.Commit()
            Console.WriteLine("Insert succeeded")

To do this, would I need to have two transaction objects?

Could somebody point me in the right direction, with example code, on how to do this?

Thanks in advance

John