Transactions and SavePoints

Hello.
I am using the Driver odbc for access to postgresql.
I have a referring problem to the cancellation of the transaction when
some error
is found at the moment of the execution of the same one.
I try to execute this sql command:

BEGIN TRANSACTION;
DELETE FROM TABL1 WHERE ID = 1;
INSERT INTO TABL1 VALUES (1,1);
SAVEPOINT SVPT;
INSERT INTO TABL1 VALUES (1,1);
ROLLBACK TO SAVEPOINT SPVT;
COMMIT;

When I try to insert as register it accuses to error with key duplicate. Ok.
But I do not want to cancel the transaction I I need to only continue
with the same one skirting this error. For this reason I am using
SavePoints but it generates the error:
"ERROR: ROLLBACK TO SAVEPOINT may only be used in transaction blocks"

Necessary of the your help.
I thank

Yours truly

--
Cleber Nardelli