How to Capture sucess messages BAPI_REPMANCONF1_CREATE_MTS

Hi Friends,

If I go to MFBF transaction:

Key in the required fields like Backflush qty, Unit of measure, posting date, document date, material, plant and production version and click on "save" button, I get a message in my status bar as "GR and GI with document 123456789 and activities posted".

I copied the BAPI_REPMANCONF1_CREATE_MTS to Z FM.

How can I capture this messages in Z FM of my return parameter of bapiret2.

I have done this in my source code of Z FM:

IF RETURN-ID = 'RM' AND RETURN-NUMBER = '191'.
    CONCATENATE 'GR and GI with document ' MAT_DOC ' and activities posted' INTO GV_MESSAGE.
    RETURN-MESSAGE = GV_MESSAGE.
  ENDIF.

When I debug - I don't see any values in my BAPIRET2. So, it is not going thru my if condition.

Am I doing anything wrong in my code? Please suggest.

Thanks.