[ADMIN] Query

[Kartik]

hello there,i am new to postgresql
i am using postgresql 8.3.3 and i am writing one whole transaction. i want
to know how to set auto commit off
because if any error occours i want the whole transaction to be rolled back.
when i tried alter database dbname set autocommit = off
then it gives me error saying autocommit not available
so can anyone suggest how to set autocommit as off so that i can rollback
the transaction..
thank you
waiting for your reply
regards
kartik