Instead-of triger creation error: Please, help

I've got an error "Message 439: ORA-00439: feature not enabled: Instead-of triggers" on execution folowing script:

CREATE OR REPLACE TRIGGER SECURITYMGR.TR_WEB_USER_TO_DELETE_DELETE INSTEAD OF DELETE
ON WEB_LOGINS_TO_DELETE
FOR EACH ROW
BEGIN
    NULL;
END; I'm wandering what and where I must do to create it?

Thanks.

-----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own Received on Thu Apr 29 1999 - 05:21:15 CDT