Dele PO in SRM 4.00

Hi,

we are trying to develop a program that can delete PO items in SRM and R3, we are excecuting the FM BBP_PD_PO_DB_DELETE_MULTI in the following way:

l_otd-guid = '479D144AA4FB3608E10000000A021B2A'.

append l_otd.

CALL FUNCTION 'BBP_PD_PO_DB_DELETE_MULTI'

EXPORTING

IV_SAVE_ON_DB = 'X'

TABLES

it_objects_to_delete = l_otd

ET_DELETED_OBJECTS = l_delted

et_messages = l_messg

after running this program the PO Item is not deleted

do I need to execute another thing ?

may be some commit function or any thing else to complete the delete ?

Tanks in advance