Custom fields update in EQUi

Hi,

I am using BAPI - BAPI_EQUI_CHANGE to update custom fields in EQUI . the custom field has been added to various ITOB structures. Here is my code ::

DATA : ls_itob   TYPE bapi_itob,
        ls_itobx  TYPE bapi_itobx,
        ls_spec   TYPE bapi_itob_eq_only,
        ls_specx  TYPE bapi_itob_eq_onlyx,
        ls_return LIKE bapiret2.

CALL FUNCTION 'BAPI_EQUI_GETDETAIL'
   EXPORTING
     equipment         = p_equnr
   IMPORTING
     data_general_exp  = ls_itob
     data_specific_exp = ls_spec
*   DATA_FLEET_EXP    =
*   RETURN            =
   .

ls_itob-ztest = abap_true.
ls_itobx-ztest = abap_true.

CALL FUNCTION 'BAPI_EQUI_CHANGE'
   EXPORTING
     equipment         = p_equnr
     data_general      = ls_itob
     data_generalx     = ls_itobx
     data_specific     = ls_spec
     data_specificx    = ls_specx
    VALID_DATE        = SY-DATUM
    VALID_TIME        = SY-UZEIT
   IMPORTING
     return            = ls_return.
.

   CALL FUNCTION 'BAPI_TRANSACTION_COMMIT'.

However it doesn't update the custom field. Any idea what could be missing ?

Existing posts in SCN weren't of help much !

regards,

AM