parameter p_spmon  type spmon default sy-datum+0(6) obligatory.
    select-options s_spmon for s031-spmon default sy-datum+0(6) obligatory.

form  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.                               "MONAT_F4

at selection-screen on value-request for p_spmon.
      perform monat_f4.
    at selection-screen on value-request for s_spmon-low.
      perform monat_f4.
    at selection-screen on value-request for s_spmon-high.
      perform monat_f4.