屏幕选择年月输入帮助

FORM frm_monat_f4 .
  DATA: BEGIN OF mf_dynpfields OCCURS 1.
          INCLUDE STRUCTURE dynpread.
  DATA: END   OF mf_dynpfields.
  DATA: mf_returncode   LIKE sy-subrc,
        mf_monat        LIKE isellist-month,
        mf_hlp_repid    LIKE sy-repid.
*  FIELD-SYMBOLS: <MF_FELD>.

  GET CURSOR FIELD mf_dynpfields-fieldname.
  APPEND mf_dynpfields.
  mf_hlp_repid = sy-repid.
  DO 2 TIMES.
    CALL FUNCTION 'DYNP_VALUES_READ'
      EXPORTING
        dyname               = mf_hlp_repid
        dynumb               = sy-dynnr
      TABLES
        dynpfields           = mf_dynpfields
      EXCEPTIONS
        invalid_abapworkarea = 01
        invalid_dynprofield  = 02
        invalid_dynproname   = 03
        invalid_dynpronummer = 04
        invalid_request      = 05
        no_fielddescription  = 06
        undefind_error       = 07.
    IF sy-subrc = 3.
      mf_hlp_repid = 'SAPLALDB'.
    ELSE.
      READ TABLE mf_dynpfields INDEX 1.
      TRANSLATE mf_dynpfields-fieldvalue USING '_ '.
      EXIT.
    ENDIF.
  ENDDO.
  IF sy-subrc = 0.
    CALL FUNCTION 'CONVERSION_EXIT_PERI_INPUT'
      EXPORTING
        input         = mf_dynpfields-fieldvalue
      IMPORTING
        output        = mf_monat
      EXCEPTIONS
        error_message = 1.
    IF mf_monat IS INITIAL.
      mf_monat = sy-datlo(6).
    ENDIF.

    CALL FUNCTION 'POPUP_TO_SELECT_MONTH'
      EXPORTING
        actual_month               = mf_monat
      IMPORTING
        selected_month             = mf_monat
        return_code                = mf_returncode
      EXCEPTIONS
        factory_calendar_not_found = 01
        holiday_calendar_not_found = 02
        month_not_found            = 03.
    IF sy-subrc = 0 AND mf_returncode = 0.
      CALL FUNCTION 'CONVERSION_EXIT_PERI_OUTPUT'
        EXPORTING
          input  = mf_monat
        IMPORTING
          output = mf_dynpfields-fieldvalue.
      COLLECT mf_dynpfields.
      CALL FUNCTION 'DYNP_VALUES_UPDATE'
        EXPORTING
          dyname               = mf_hlp_repid
          dynumb               = sy-dynnr
        TABLES
          dynpfields           = mf_dynpfields
        EXCEPTIONS
          invalid_abapworkarea = 01
          invalid_dynprofield  = 02
          invalid_dynproname   = 03
          invalid_dynpronummer = 04
          invalid_request      = 05
          no_fielddescription  = 06
          undefind_error       = 07.
    ENDIF.
  ENDIF.
ENDFORM.                    " FRM_MONAT_F4