About Release contract used FM "BBP_PD_CTR_STATUS_CHANGE"

Dear all,

     We need batch release the contract,Now we create a program call FM "BBP_PD_CTR_STATUS_CHANGE",The source code follow as :

   REPORT  Z_CTR6.
data:l_guid type CRMD_ORDERADM_H-GUID,
     it_mess like BBP_PDS_MESSAGES OCCURS 0 WITH HEADER LINE.

select SINGLE guid INTO l_guid from CRMD_ORDERADM_H where Object_ID = '4400000109'
and Object_Type = 'BUS2000113'.
CALL FUNCTION 'BBP_PD_CTR_STATUS_CHANGE'
   EXPORTING
    I_GUID             = l_guid
*    IV_ITEM_GUID       =
     I_ACTIVITY         = 'LDRC'
    I_SAVE_DB          = 'X'
*    I_TEST_RUN         =
   TABLES
     E_MESSAGES         = it_mess
*  CHANGING
*    E_CHANGED          =
           .

CALL FUNCTION 'BAPI_TRANSACTION_COMMIT'
* EXPORTING
*   WAIT          =
* IMPORTING
*   RETURN        =
          .

But the FM return message ""Release Contract" is not allowed (Purchasing Contract 4400000109)"..

Who can help me?