REFRESH IT_MSEG.
            CLEAR IT_MSEG.

SELECT * INTO CORRESPONDING FIELDS OF TABLE IT_MSEG
                     FROM MSEG WHERE MBLNR = TITAB-MBLNR
                                 AND MJAHR = TITAB-MJAHR
                                 AND ZEILE = TITAB-ZEILE.
            LOOP AT IT_MSEG.
                  IF IT_MSEG-SGTXT = ''.
                     IT_MSEG-SGTXT = '1'.
                  ELSE.
                     IT_MSEG-SGTXT = IT_MSEG-SGTXT + 1.
                  ENDIF.
                  MODIFY IT_MSEG.
                  CLEAR IT_MSEG.
            ENDLOOP.

CALL FUNCTION 'MB_CHANGE_DOCUMENT'
              TABLES
                ZMKPF         = IT_MKPF
                ZMSEG         = IT_MSEG.
            IF SY-SUBRC = 0.
                 CALL FUNCTION 'BAPI_TRANSACTION_COMMIT'
                 EXPORTING
                   WAIT          = 'X'.
            ELSE.
                 CALL FUNCTION 'BAPI_TRANSACTION_ROLLBACK'.
            ENDIF.