Please assist with database event trigger

Hi all,

Been banging my head out trying to get this trigger to work. Oracle version is 8.1.6.2 on Solaris 2.6

The trigger is valid, it simply does not alter the session like it is supposed to. Can anyone point me in the right direction?

CREATE OR REPLACE TRIGGER aradmin.logon_trigger AFTER LOGON on database
DECLARE
cur1id integer;
BEGIN
IF LOGIN_USER ='ARADMIN' THEN
cur1id:=dbms_sql.open_cursor;
dbms_sql.parse (cur1id,'alter session set nls_date_format=''DD-MON-YYYY'' ' ,dbms_sql.native);
dbms_sql.close_cursor(cur1id);
END IF;
END;
/

TIA,

--
Dave A