Forwarding mail through SWW_WI_FORWARD

Hi guys

i am trying to forward SAP mail through this function SWW_WI_FORWARD but i encounter a forwarding error=2

source codes below.  Can anyone be able to advise where goes wrong or what kind of authorisation required?

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source codes:=======

CALL FUNCTION 'SWW_WI_FORWARD'

EXPORTING

current_user = f_userid

wi_id = f_wild

do_commit= 'X'

preconditions_checked = 'X'

TABLES

new_agents = iuser

EXCEPTIONS

invalid_status=1

update_failed=2

invalid_type = 3

OTHERS=4

i also realised myid is captured in table SWWVEAGENT (excluded agents of work items), how can i get myid as agents of work items?

thank you.

Regards