As I said earlier, the BEGIN TRAN, COMMIT TRAN, and ROLLBACK TRAN commands are used to manage transactions in Transact-SQL. (The sp_xxxx_xact system stored procedures are legacy code that was used in the past with DB-Library two-phase commit applications, and you should not use them.) The exact syntax used to begin a transaction is:
BEGIN TRAN[SACTION] [name|@TranNameVar]
To commit a transaction, use:
COMMIT TRAN[SACTION] [name|@TranNameVar]
And to roll back a transaction, use:
ROLLBACK TRAN[SACTION] [name|@TranNameVar]
You can also use the COMMIT WORK and ROLLBACK WORK commands in lieu of COMMIT TRANSACTION and ROLLBACK TRANSACTION, though you cannot use transaction names with them.