1.Thanks for the info. I think that I got the idea (in the meantime I browse MSDN a little bit).
2.With ODBC if several connections participate in the same transactions there is a need to bind the connection together through executing sp_getbindtoken and sp_bindsession stored procedures (SQL Server). When you do this any of the connections can start and end the transaction.

>Jozef,
>
>Not sure, i only use COM+ MSDTC transactions, but just a guess: use the same connection object to call your updates, if any fails call the RollbackTrans() of the connection.
>
>What do you mean about the use of "token" with ODBC? just curious.
>
>Stephane
>
>>Hi Stephane ! Thanks for quick answer. But what if several tables participate in the same transaction ? With ODBC we have to use token to bind several connection together. How can this such task be done with ADO.
>>
>>
>>>Transactions are set at the connection level, oConn.BeginTrans, oConn.CommitTrans and oConn.RollbackTrans.
>>>
>>>If you are using COM+ it's much easier to use the built-in transaction support of COM+.
>>>
>>>>I know how to how to deal with transactions using ODBC but I want to try to do it with ADO. Does anybody know how to deal with transactions using cursorsoradapters (datasourcetype=ADO) connected to SQLServer backend.
>>>>I would apreciate a link to such information.
>>>>(In case of my application several tables participate in the same transaction)