Sql fetch cursors

DECLARE
slip_Update CURSOR FOR
SELECT * FROM SlipsTEST, SlipdetailsTEST
WHERE SlipsTEST.SlipIdOld = SlipdetailsTEST.SlipIdOld
FOR UPDATE;
BEGIN
OPEN slip_Update;
FOR slip_Update IN slip_Update
LOOP
UPDATE SlipdetailsTEST
SET SlipdetailsTEST.SNO = SlipsTEST.SNO
WHERE CURRENT OF slip_Update;
END LOOP;
CLOSE slip_Update;
END;