Bapi_contract_create extensionIn

Hi,

I have a bapi "BAPI_CONTRACT_CREATE". It is required to store some data in custom fields in EKPO table. Therefore, I used extensionIn. However, after creating a document, the custom fields in EKPO table is empty.

DATA: ext_container TYPE TABLE OF bapiparex WITH HEADER LINE,
              bapi_te_item TYPE BAPI_TE_MEOUTITEM,
              bapi_te_itemx TYPE BAPI_TE_MEOUTITEMX .

        bapi_te_item-item_no = ''.
        bapi_te_item-ZZRESALE = 'X'.
        bapi_te_item-ZEQUIPMENT = 'X'.
        bapi_te_item-ZREFUBSHMENT = 'X'.

        bapi_te_itemx-item_no = ''.
        bapi_te_itemx-ZZRESALE = 'X'.
        bapi_te_itemx-ZEQUIPMENT = 'X'.
        bapi_te_itemx-ZREFUBSHMENT = 'X'.

        ext_container-structure = 'BAPI_TE_MEOUTITEM'.
        ext_container-valuepart1 = bapi_te_item.
        APPEND ext_container.
        CLEAR: ext_container.

        ext_container-structure = 'BAPI_TE_MEOUTITEMX'.
        ext_container-valuepart1 = bapi_te_itemx.
        APPEND ext_container.

        CALL FUNCTION 'BAPI_CONTRACT_CREATE'
          EXPORTING
            header             = wa_header
            headerx            = wa_headerx
          IMPORTING
            purchasingdocument = gv_ebeln
          TABLES
            return             = it_return
            extensionin        = ext_container[]
            item               = it_item
            itemx              = it_itemx.

          CALL FUNCTION 'BAPI_TRANSACTION_COMMIT'
            EXPORTING
              wait = 'X'.