F3 function key not work in this ALV pgm

Question

Hi,
How to make the F3 function key (go back to previous screen) work in this ALV program?
Thanks,
Helen
REPORT  z_pgm.
TYPE-POOLS : slis.
INITIALIZATION.
  PERFORM sub_fieldcat_init CHANGING gi_fieldcat.
  PERFORM sub_eventtab_build USING gi_events[].
  PERFORM sub_event_exit_build CHANGING gi_event_exit.
  CALL FUNCTION 'REUSE_ALV_VARIANT_DEFAULT_GET'
    EXPORTING
      i_save     = g_save
    CHANGING
      cs_variant = g_xvariant
    EXCEPTIONS
      not_found  = 2.
*EVENT : AT SELECTION-SCREEN OUTPUT                                    *
AT SELECTION-SCREEN OUTPUT.
           EVENT : START-OF-SELECTION
START-OF-SELECTION.
  PERFORM sub_comment_build  USING gi_list_top_of_page.
  PERFORM sub_get_data.
           EVENT : END-OF-SELECTION
END-OF-SELECTION.
  IF l_error IS INITIAL.
    PERFORM sub_grid_display USING gi_adrc_disp.
  ENDIF.
*&      Form  sub_fieldcat_init
FORM sub_fieldcat_init CHANGING li_fieldcat LIKE gi_fieldcat[]."#EC *
  DATA : lw_fieldcat TYPE slis_fieldcat_alv.
  REFRESH gi_fieldcat[].
  CLEAR lw_fieldcat.
  lw_fieldcat-fieldname = 'SELKZ'.
  lw_fieldcat-tabname   = 'gi_adrc_disp'.
  lw_fieldcat-hotspot   = 'X'.
  lw_fieldcat-outputlen = '8'.
  APPEND lw_fieldcat TO li_fieldcat.
  CLEAR lw_fieldcat.
  lw_fieldcat-fieldname = 'LOCATION'.
  lw_fieldcat-tabname   = 'gi_adrc_disp'.
  lw_fieldcat-seltext_s = text-002.
  lw_fieldcat-seltext_m = text-002.
  lw_fieldcat-seltext_l = text-002.
  lw_fieldcat-outputlen = '20'.
  APPEND lw_fieldcat TO li_fieldcat.
ENDFORM.                    " sub_fieldcat_init
*&      Form  SUB_EVENTTAB_BUILD
FORM sub_eventtab_build  USING    li_events TYPE slis_t_event.
  DATA: lw_event TYPE slis_alv_event.
*to call top_of_page event
  CALL FUNCTION 'REUSE_ALV_EVENTS_GET'
    EXPORTING
      i_list_type = 0
    IMPORTING
      et_events   = li_events.
  READ TABLE li_events WITH KEY name =  slis_ev_top_of_page
                           INTO lw_event.
  IF sy-subrc = 0.
    MOVE c_formname_top_of_page TO lw_event-form.
    APPEND lw_event TO li_events.
  ENDIF.
ENDFORM.                    " SUB_EVENTTAB_BUILD
      FORM SUB_COMMENT_BUILD                                        *
FORM sub_comment_build USING li_lt_top_of_page TYPE slis_t_listheader.
  DATA: lw_line TYPE slis_listheader.
Listenüberschrift: Typ H
  CLEAR lw_line.
  lw_line-typ  = 'H'.
  lw_line-info = text-013.
  APPEND lw_line TO li_lt_top_of_page.
Kopfinfo: Typ S
  CLEAR lw_line.
  lw_line-typ  = 'S'.
  lw_line-key  = text-014.
  lw_line-info = text-015.
  APPEND lw_line TO li_lt_top_of_page.
ENDFORM.                    "SUB_COMMENT_BUILD
*&      Form  sub_VARIANT_INIT
FORM sub_variant_init .
  CLEAR g_variant.
  g_variant-report = g_repid.
ENDFORM.                    " sub_VARIANT_INIT
*&      Form  SUB_F4_FOR_VARIANT
      To get the existing variant
FORM sub_f4_for_variant .
  g_variant-report = g_repid.
  CALL FUNCTION 'REUSE_ALV_VARIANT_F4'
         EXPORTING
              is_variant          = g_variant
              i_save              = g_save
            it_default_fieldcat =
         IMPORTING
              e_exit              = g_exit
              es_variant          = g_xvariant
         EXCEPTIONS
              not_found = 2.
  IF sy-subrc = 2.
    MESSAGE ID sy-msgid TYPE 'S'      NUMBER sy-msgno
            WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.
  ELSE.
  ENDIF.
ENDFORM.                    " SUB_F4_FOR_VARIANT
      FORM TOP_OF_PAGE
FORM top_of_page.                                           "#EC CALLED
  CALL FUNCTION 'REUSE_ALV_COMMENTARY_WRITE'
    EXPORTING
      it_list_commentary = gi_list_top_of_page.
ENDFORM.                    "TOP_OF_PAGE
FORM sub_grid_display USING li_final_disp LIKE gi_final_disp.
    CALL FUNCTION 'REUSE_ALV_GRID_DISPLAY'                  "#EC *
      EXPORTING
        i_callback_pf_status_set = 'SET_PF_STATUS'
        i_callback_program       = g_repid
        i_callback_user_command  = 'SUB_CB_USER_COMMAND'
      i_grid_title       = l_title
        it_fieldcat              = gi_fieldcat
       is_layout          = gw_layout
        i_save                   = g_save
        is_variant               = g_variant
        it_events                = gi_events[]
        it_event_exit            = gi_event_exit[]
      IMPORTING
        e_exit_caused_by_caller  = g_exit_caused_by_caller
        es_exit_caused_by_user   = gs_exit_caused_by_user
      TABLES
        t_outtab                 = gi_adrc_disp
      EXCEPTIONS
        program_error            = 1
        OTHERS                   = 2.
ENDFORM.                    " sub_grid_display
*&      Form                                          *
FORM sub_get_data .
  CLEAR l_error.
  IF NOT rb_loc IS INITIAL.
    IF p_loc EQ space.
      MESSAGE i100(zm01) WITH
              'Please Enter Location Code and SET ID'.
      l_error = 'X'.
    ENDIF.
    SELECT addrnumber location name1 name2 building floor
               name_co country street str_suppl1 str_suppl3 city1
               city2 region post_code1 transpzone
            INTO TABLE gi_adrc_disp
            FROM adrc
            WHERE region = p_region
              AND str_suppl3 = p_loc.
  ELSEIF NOT rb_all IS INITIAL.
    SELECT addrnumber location name1 name2 building floor
               name_co country street str_suppl1 str_suppl3 city1
               city2 region post_code1 transpzone
            INTO TABLE gi_adrc_disp
            FROM adrc
            WHERE transpzone NE space.
  ENDIF.
  IF sy-subrc NE 0.
    l_error = 'X'.
    MESSAGE i100(zm01) WITH
              'No Record Exists for Input'.
    EXIT.
  ENDIF.
  lw_adrc-selkz = c_add.
  MODIFY gi_adrc_disp FROM lw_adrc TRANSPORTING selkz
        WHERE transpzone = space.
  lw_adrc-selkz = c_remove.
  MODIFY gi_adrc_disp FROM lw_adrc TRANSPORTING selkz
        WHERE transpzone NE space.
ENDFORM.                    " sub_get_data
*&      Form  sub_cb_user_command
FORM sub_cb_user_command  USING r_ucomm LIKE sy-ucomm                               rs_selfield TYPE slis_selfield.
   l_index = rs_selfield-tabindex.
  ENDFORM.                        "sub_cb_user_command
*&      Form  sub_cb_user_command
FORM set_pf_status USING rt_extab TYPE slis_t_extab.
  SET PF-STATUS 'MAIN'.
ENDFORM.                        "set_pf_status

Answer 1

Hi,
this is for setting the PF-status.
FORM set_pf_status USING rt_extab TYPE slis_t_extab.
SET PF-STATUS 'MAIN'.
ENDFORM. "set_pf_status
and double click on main and see what is the Function key and function code associated for BACK.
FORM sub_cb_user_command USING r_ucomm LIKE sy-ucomm
rs_selfield TYPE slis_selfield.
case r_ucomm.
when <b>'BACK'.</b>  <<<<i assumed Focde is BACK for BACK
leave to screen 0.
endform.
Regards
vijay