'run_addm' error

Oracle 10.2.0.3 When I run the following script as sys: SET PAGESIZE 0 LONG 1000000 LONGCHUNKSIZE 1000; COLUMN get_clob FORMAT a80; -- execute run_addm() with 7pm and 9pm as input VARIABLE task_name VARCHAR2(30); BEGIN :task_name := run_addm( TO_DATE('18:00:00 (04/03)', 'HH24:MI:SS (MM/ DD)'), TO_DATE('20:00:00 (04/03)', 'HH24:MI:SS (MM/