ALV-Save tab not fucntion in PF status

Question

Following report that I have has a PF status Save which when clicked should mark the selected documenst in the output as selected and save . But in my report this is not happeining , it checks the doc when I press save but when I og out of the report and come back again it dosen show me the saved items as checked and shows just as before. Can anyone help me out pls.
*& Report  ZSD_PRINT_CONFIRMATION
REPORT  ZSD_PRINT_CONFIRMATION LINE-SIZE 190 LINE-COUNT 60
        no standard page heading.
TYPE-POOLS: slis.
TABLES: vbrk, vbrp, vbpa.
*&     Selection-Screen
SELECTION-SCREEN BEGIN OF BLOCK block1 WITH FRAME TITLE text-000.
SELECT-OPTIONS: s_vbeln  FOR  vbrk-vbeln,      " billing doc.
                s_kunnr  FOR  vbpa-kunnr,      " bill-to customer number.
                s_werks  FOR  vbrp-werks,      " line item plant.
                s_fkdat  FOR  vbrk-fkdat,      " billing date.
                s_fkart  FOR  vbrk-fkart,      " billing type.
                s_vkorg  FOR  vbrk-vkorg.      " sales org.
PARAMETERS    : p_hold as CHECKBOX.
SELECTION-SCREEN END OF BLOCK block1.
SELECTION-SCREEN BEGIN OF BLOCK block2 WITH FRAME TITLE text-024.
PARAMETERS    : pa_vari TYPE slis_vari DEFAULT ' '. " Display Variant.
SELECTION-SCREEN END OF BLOCK block2.
*& Internal Tables, Work Areas, Work Variables and Constants
* Storing Extracted Info.
TYPES: BEGIN OF t_extract,
         sel  type  C,
         count type I,
         vbeln        TYPE vbeln_vf,   " Billing document.
         posnr        TYPE posnr,      " line item.
         fkart        TYPE fkart,      " billing type.
         vtext        TYPE BEZEI20,    " billing type description.
         fkdat        TYPE fkdat,      " billing date.
         werks        TYPE werks_d,    " line item plant.
         werks_name1  TYPE name1,      " plant description.
         kunnr        TYPE kunnr,      " bill-to customer.
         kunnr_name1  TYPE name1_gp,   " bill-to description.
         netwr        TYPE netwr,      " net value,invoice total dollar
         zzflag       TYPE boolean,    " hold or print indicator
         zzreason     TYPE char30,     " reason being held
         zzuser       TYPE ernam,      " last changed by
         zz_changed_date TYPE dats,    " last changed date
         zz_changed_time TYPE tims,    " last changed time
        END OF t_extract.
DATA: it_extract  TYPE TABLE OF t_extract,
      it_extract2 TYPE TABLE OF t_extract,
      wa_extract  LIKE LINE  OF it_extract,
      wa_selected LIKE LINE  OF it_extract,
      wa_extract3 LIKE LINE  OF it_extract.
DATA: t_vbrk      TYPE TABLE OF vbrk,
      wa_vbrk     LIKE LINE OF t_vbrk.
* ALV data declaration
DATA: fieldcatalog TYPE slis_t_fieldcat_alv WITH HEADER LINE,
      gd_tab_group TYPE slis_t_sp_group_alv,
      gd_layout    TYPE slis_layout_alv,
      gd_repid     LIKE sy-repid.
* messages as result of processing in program, will be displayed
* at end of processing.
TYPES: BEGIN OF t_msg,
         vbeln        TYPE vbeln_vf,   " Billing document.
         dummy        TYPE c,
         message      TYPE CHAR80,
       END OF t_msg.
DATA: it_msg TYPE TABLE OF t_msg,
      wa_msg LIKE LINE OF it_msg,
      w_idx2 type sy-tabix,
      w_idx3 type sy-tabix.
CONSTANTS: c_zog2 TYPE vbrk-fkart value 'ZOG2',
           c_zol2 TYPE vbrk-fkart value 'ZOL2',
           c_zre  TYPE vbrk-fkart value 'ZRE ',
           c_s1   TYPE vbrk-fkart value 'S1  '.
*&     main body of processing logic
START-OF-SELECTION.
  IF s_vbeln[] IS INITIAL
    AND s_kunnr[] IS INITIAL
    AND s_werks[] IS INITIAL
    AND s_fkdat[] IS INITIAL
    AND s_fkart[] IS INITIAL
    AND s_vkorg[] IS INITIAL.
      MESSAGE s999(z001) WITH 'Please Enter Selections'(011).
  ELSE.
    PERFORM extract_data.
  ENDIF.
END-OF-SELECTION.
*  SET PF-STATUS 'STAT1000'.
  IF s_vbeln[] IS INITIAL
    AND s_kunnr[] IS INITIAL
    AND s_werks[] IS INITIAL
    AND s_fkdat[] IS INITIAL
    AND s_fkart[] IS INITIAL
    AND s_vkorg[] IS INITIAL.
      MESSAGE s999(z001) WITH 'Please Enter Selections'(011).
  ELSE.
    IF it_extract2[] IS INITIAL.
      MESSAGE s999(z001) WITH 'No Data Selected for this criteria'(002).
    ELSE.
      PERFORM field_catalog.
      PERFORM show_report.
    ENDIF.
  ENDIF.
*&    U S E R   C O M M A N D
AT USER-COMMAND.
* accommodated at teh end or report********
*  CASE sy-ucomm.
*    WHEN 'SELE'.
*      PERFORM update_itab_from_screen.
*      LOOP AT it_extract2 INTO wa_extract.
*        wa_extract-zzflag = 'X'.
*        MODIFY it_extract2 FROM wa_extract.
*      ENDLOOP.
*      PERFORM show_report.
*    WHEN 'DSEL'.
*      PERFORM update_itab_from_screen.
*      LOOP AT it_extract2 INTO wa_extract.
*        clear wa_extract-zzflag.
*        MODIFY it_extract2 FROM wa_extract.
*      ENDLOOP.
*      PERFORM show_report.
*    WHEN 'EXIT'.
*      leave to screen 0.
*    WHEN OTHERS.
*      MESSAGE S999(Z001) WITH 'Inactive Key, Try Again'(001).
*  ENDCASE.
*&    LINE SELECTION
AT LINE-SELECTION.
  PERFORM update_itab_from_screen.
  REFRESH it_msg.
* Upate vbrk append structure
  LOOP AT it_extract2 INTO wa_extract.
    w_idx2 = sy-tabix.
* if flag is on, there must be a reason
    if NOT wa_extract-zzflag is initial.
      if wa_extract-zzreason is initial.
        wa_msg-vbeln = wa_extract-vbeln.
        wa_msg-message =  'For Hold doc.,Reason required'(017).
        append wa_msg to it_msg.
        continue.
      endif.
    endif.
* only if the flag or reason has been changed with what's in database vbrk
* which was read in the beginning of program and stored in
* it_extract.
    read table it_extract into wa_extract3
      with key vbeln = wa_extract-vbeln.
    w_idx3 = sy-tabix.
    if sy-subrc = 0.
      if wa_extract3-zzflag <> wa_extract-zzflag
      or wa_extract3-zzreason <> wa_extract-zzreason.
        PERFORM update_vbrk.
      endif.
    endif.
  ENDLOOP.
* display an updated list.
  PERFORM show_report.
* display processing messages
* popup with table display ok has 'print' functionality but
* titletext is not working. One option is to copy following
* and fix titletext.
CALL FUNCTION 'POPUP_WITH_TABLE_DISPLAY_OK'
  EXPORTING
    ENDPOS_COL         = 35
    ENDPOS_ROW         = 15
    STARTPOS_COL       = 1
    STARTPOS_ROW       = 1
    TITLETEXT          = 'Results'
* IMPORTING
*   CHOISE             =
  TABLES
    VALUETAB           = it_msg.
* EXCEPTIONS
*   BREAK_OFF          = 1
*   OTHERS             = 2
IF SY-SUBRC <> 0.
* MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
*         WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
* wrf popup with table display has no 'print' capability
* but titletext is working.
*CALL FUNCTION 'WRF_POPUP_WITH_TABLE_DISPLAY'
*  EXPORTING
*    ENDPOS_COL         = 35
*    ENDPOS_ROW         = 15
*    STARTPOS_COL       = 1
*    STARTPOS_ROW       = 1
*    TITLETEXT          = 'Results'
*  TABLES
*    VALUETAB           = it_msg.
*&    LINE SELECTION
TOP-OF-PAGE.
* same as top-of-page during line-selection
  WRITE: 3 text-003, 14 text-013, 45 text-014, 58 text-015,
         69 text-016, 78 text-004, 88 text-005, 104 text-006,
         115 text-007, 121 text-008, 136 text-009,
         147 text-010, 173 text-012, 186 text-023,
         / sy-uline.
  FORMAT INTENSIFIED OFF COLOR OFF.
TOP-OF-PAGE DURING LINE-SELECTION.
  WRITE: 3 text-003, 14 text-013, 45 text-014, 58 text-015,
         69 text-016, 78 text-004, 88 text-005, 104 text-006,
         115 text-007, 121 text-008, 136 text-009,
         147 text-010, 173 text-012,186 text-023,
         / sy-uline.
  FORMAT INTENSIFIED OFF COLOR OFF.
*&      Form  show_report
*       Report to Display Available Orders on Screen
FORM show_report .
  DATA: l_idx TYPE i.
  l_idx = 0.
data: GS_layout TYPE slis_layout_alv.
gd_layout-zebra = 'X'.
gd_layout-colwidth_optimize = 'X'.
gd_layout-box_fieldname = 'SEL'.
gd_layout-f2code = 'SAVE'.
CALL FUNCTION 'REUSE_ALV_GRID_DISPLAY'
EXPORTING
   I_CALLBACK_PROGRAM                = sy-repid
   I_CALLBACK_PF_STATUS_SET          = 'SET_PF_STATUS'
   I_CALLBACK_USER_COMMAND           = 'USER_COMMAND'
   I_CALLBACK_TOP_OF_PAGE            = 'TOP_OF_PAGE'
   IS_LAYOUT                         = GD_LAYOUT
   IT_FIELDCAT                       = fieldcatalog[]
*   I_DEFAULT                         = 'X'
   I_SAVE                            = 'A'
*   IS_VARIANT                        =
  TABLES
    T_OUTTAB                          = it_extract2
EXCEPTIONS
   PROGRAM_ERROR                     = 1
   OTHERS                            = 2
IF SY-SUBRC <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
         WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
*  LOOP AT it_extract2 INTO wa_extract.
*    IF l_idx EQ 0.
*      FORMAT COLOR COL_NORMAL INTENSIFIED ON.
*      l_idx = 1.
*    ELSE.
*      FORMAT COLOR COL_NORMAL INTENSIFIED OFF.
*      l_idx = 0.
*    ENDIF.
*    WRITE: / wa_extract-zzflag AS CHECKBOX,
*      3 wa_extract-vbeln,        "UNDER 'Bill.Doc'(003),
*     14 wa_extract-zzreason input on, "UNDER 'Reason'(013),
*     45 wa_extract-zzuser,       "UNDER 'User'(014),
*     58 wa_extract-zz_changed_date,  "Chngd Date(015),
*     69 wa_extract-zz_changed_time,  "Time(016).
*     78 wa_extract-fkart,        "UNDER 'Bill.Type'(004),
*     83 wa_extract-vtext,        "UNDER 'Description'(005),
*    104 wa_extract-fkdat,       "UNDER 'Bill.Date'(006),
*    115 wa_extract-werks,       "UNDER 'Plant'(007),
*    120 wa_extract-werks_name1(15), "UNDER 'Plt Descrptn'(008),
*    136 wa_extract-kunnr,       "UNDER 'Bill-to'(009),
*    147 wa_extract-kunnr_name1(15), "UNDER 'Name'(010),
*    163 wa_extract-netwr,       "UNDER 'Net Value'(012),
*    180 wa_extract-count.
*  ENDLOOP.
ENDFORM.                    " show_report
*&      Form  extract_data
*       text
*  -->  p1        text
*  <--  p2        text
FORM extract_data .
  CLEAR: it_extract.  REFRESH: it_extract.
* read and select all billing documents
   IF p_hold is not initial.
SELECT vbrk~vbeln vbrk~fkart vbrk~fkdat vbrk~netwr
           vbrk~zzflag vbrk~zzreason vbrk~zzuser
           vbrk~zz_changed_date vbrk~zz_changed_time
           vbrp~posnr vbrp~werks
      INTO CORRESPONDING FIELDS OF TABLE it_extract
      FROM vbrk INNER JOIN vbrp ON
           vbrk~vbeln = vbrp~vbeln
     WHERE vbrk~vbeln IN s_vbeln
       AND vbrk~fkart IN s_fkart
       AND vbrk~fkdat IN s_fkdat
       AND vbrk~vkorg IN s_vkorg
       AND vbrk~fksto NE 'X'
       AND vbrp~werks IN s_werks.
  ELSE.
* read and select billing documents
  SELECT vbrk~vbeln vbrk~fkart vbrk~fkdat vbrk~netwr
         vbrk~zzflag vbrk~zzreason vbrk~zzuser
         vbrk~zz_changed_date vbrk~zz_changed_time
         vbrp~posnr vbrp~werks
    INTO CORRESPONDING FIELDS OF TABLE it_extract
    FROM vbrk INNER JOIN vbrp ON
         vbrk~vbeln = vbrp~vbeln
   WHERE vbrk~vbeln IN s_vbeln
     AND vbrk~fkart IN s_fkart
     AND vbrk~fkart NE c_zog2             "NAL credit memo
     AND vbrk~fkart NE c_zol2             "NAL debit memo
     AND vbrk~fkart NE c_zre              "NAL credit for returns
* testing revealed that fksto = X (cancelled) is blank while
* fkart is S1, cancelled invoice. Need to check both fields.
     AND vbrk~fkart NE c_S1               "cancelled invoice
     AND vbrk~fkdat IN s_fkdat
     AND vbrk~vkorg IN s_vkorg
     AND vbrk~fksto NE 'X'
     AND vbrp~werks IN s_werks.
  IF sy-subrc <> 0.
    MESSAGE s999(z001) WITH 'No Data Selected for this criteria'(002).
  ENDIF.
ENDIF.
  CHECK sy-subrc = 0.
* only need first line item for this report.
  SORT it_extract BY vbeln posnr.
  DELETE ADJACENT DUPLICATES FROM it_extract COMPARING vbeln.
  LOOP AT it_extract INTO wa_extract.
* Retrieve and select by sales order bill-to on header level
* as well as lookup bill-to customer name/description
    SELECT SINGLE kunnr FROM vbpa INTO wa_extract-kunnr
     WHERE vbeln = wa_extract-vbeln
       AND posnr = '000000'
       AND parvw = 'RE'.
    IF wa_extract-kunnr IN s_kunnr.
      wa_extract-kunnr_name1 = zcl_kna1=>get_name1( wa_extract-kunnr ).
    ELSE.
      DELETE it_extract.
      CONTINUE.
    ENDIF.
* lookup billing type description
    SELECT SINGLE vtext FROM tvfkt
      INTO wa_extract-vtext
     WHERE spras = sy-langu
       AND fkart = wa_extract-fkart.
    IF sy-subrc <> 0.
      clear wa_extract-vtext.
    ENDIF.
* lookup plant description
    SELECT SINGLE name1 FROM t001w
      INTO wa_extract-werks_name1
     WHERE werks = wa_extract-werks.
    IF sy-subrc <> 0.
      clear wa_extract-werks_name1.
    ENDIF.
wa_extract-count = 1.
    APPEND wa_extract TO it_extract2.
  ENDLOOP.
ENDFORM.                    " extract_data
*&      Form  update_itab_from_screen
*       text
*  -->  p1        text
*  <--  p2        text
FORM update_itab_from_screen .
  DO.
    READ LINE sy-index FIELD VALUE wa_extract-zzflag wa_extract-vbeln
                                   wa_extract-zzreason.
    IF sy-subrc NE 0.
      EXIT.
    ELSE.
      CALL FUNCTION 'CONVERSION_EXIT_ALPHA_INPUT'
        EXPORTING
          input  = wa_extract-vbeln
        IMPORTING
          output = wa_extract-vbeln.
      READ TABLE it_extract2 INTO wa_selected
           WITH KEY vbeln = wa_extract-vbeln.
      IF sy-subrc EQ 0.
        wa_selected-zzflag = wa_extract-zzflag.
        wa_selected-zzreason = wa_extract-zzreason.
        MODIFY it_extract2 FROM wa_selected INDEX sy-tabix.
      ENDIF.
    ENDIF.
  ENDDO.
ENDFORM.                    " update_itab_from_screen
*&      Form  update_vbrk
*       text
*  -->  p1        text
*  <--  p2        text
FORM update_vbrk .
* read the current version of the corresponding billing doc. from vbrk
* in case it has been changed.
  SELECT single * FROM VBRK INTO wa_vbrk
   WHERE vbeln = wa_extract-vbeln.
  IF sy-subrc <> 0.
    wa_msg-vbeln = wa_extract-vbeln.
    wa_msg-message = 'Billing Doc. Not Found. Contact Support'(018).
    append wa_msg to it_msg.
  ENDIF.
* lock the same billing doc.
  CHECK sy-subrc = 0.
  CALL FUNCTION 'ENQUEUE_EVVBRKE'
   EXPORTING
     MODE_VBRK            = 'E'
     MANDT                = SY-MANDT
     VBELN                = wa_extract-vbeln
     X_VBELN              = ' '
     _SCOPE               = '2'
     _WAIT                = ' '
     _COLLECT             = ' '
   EXCEPTIONS
     FOREIGN_LOCK         = 1
     SYSTEM_FAILURE       = 2
     OTHERS               = 3.
  IF SY-SUBRC <> 0.
    wa_msg-vbeln = wa_extract-vbeln.
    wa_msg-message = 'Unable To Lock'(019).
    append wa_msg to it_msg.
* MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
*         WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
  ELSE.
* Update the corresponding billing doc. in vbrk
*    wa_vbrk-zzflag = wa_extract-zzflag.
*    wa_vbrk-zzreason = wa_extract-zzreason.
*    wa_vbrk-zzuser = sy-uname.
*    wa_vbrk-zz_changed_date = sy-datum.
*    wa_vbrk-zz_changed_time = sy-uzeit.
*    wa_extract3-zzflag = wa_vbrk-zzflag.
*    wa_extract3-zzreason = wa_vbrk-zzreason.
*    wa_extract3-zzuser = wa_vbrk-zzuser.
*    wa_extract3-zz_changed_date = wa_vbrk-zz_changed_date.
*    wa_extract3-zz_changed_time = wa_vbrk-zz_changed_time.
    UPDATE vbrk FROM wa_vbrk.
    IF sy-subrc = 0.
      CALL FUNCTION 'DEQUEUE_EVVBRKE'
        EXPORTING
        MODE_VBRK       = 'E'
        MANDT           = SY-MANDT
        VBELN           = wa_extract-vbeln
        X_VBELN         = ' '
        _SCOPE          = '3'
        _SYNCHRON       = ' '
        _COLLECT        = ' '.
      if sy-subrc = 0.
        wa_msg-vbeln = wa_extract-vbeln.
        wa_msg-message = 'Billing Document Updated'(022).
        append wa_msg to it_msg.
        modify it_extract index w_idx3 from wa_extract3
          transporting zzflag zzreason zzuser zz_changed_date zz_changed_time.
        modify it_extract2 index w_idx2 from wa_extract3
          transporting zzuser zz_changed_date zz_changed_time.
      else.
        wa_msg-vbeln = wa_extract-vbeln.
        wa_msg-message = 'Unable To unLock Document'(021).
        append wa_msg to it_msg.
      endif.
    ELSE.
      wa_msg-vbeln = wa_extract-vbeln.
      wa_msg-message = 'Failed to Update Document'(020).
      append wa_msg to it_msg.
    ENDIF.
  ENDIF.
ENDFORM.                    " update_vbrk
*&      Form  FIELD_CATALOG
*       text
*  -->  p1        text
*  <--  p2        text
FORM field_catalog .
  fieldcatalog-fieldname   = 'SEL'.
  fieldcatalog-seltext_m   = 'Select'.
  fieldcatalog-col_pos     = 19.
  fieldcatalog-checkbox = 'X'.
  fieldcatalog-edit = 'X'.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'VBELN'.
  fieldcatalog-seltext_m   = 'Billing document'.
  fieldcatalog-col_pos     = 23.
  fieldcatalog-outputlen   = 10.
  fieldcatalog-emphasize   = 'X'.
*  fieldcatalog-key         = 'X'.
  fieldcatalog-hotspot     = 'X'.
*  fieldcatalog-edit = 'X'.
*  fieldcatalog-do_sum      = 'X'.
*  fieldcatalog-no_zero     = 'X'.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
*  fieldcatalog-fieldname   = 'POSNR'.
*  fieldcatalog-seltext_m   = 'line item'.
*  fieldcatalog-col_pos     = 1.
*  APPEND fieldcatalog TO fieldcatalog.
*  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'FKART'.
  fieldcatalog-seltext_m   = 'Billing Type'.
  fieldcatalog-col_pos     = 30.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'VTEXT'.
  fieldcatalog-seltext_m   = 'Billing Type Description'(030).
  fieldcatalog-col_pos     = 31.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'FKDAT'.
  fieldcatalog-seltext_m   = 'Billing Date'.
  fieldcatalog-col_pos     = 32.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'WERKS'.
  fieldcatalog-seltext_m   = 'Line Item Plant'.
  fieldcatalog-col_pos     = 33.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'WERKS_NAME1'.
  fieldcatalog-seltext_m   = 'Plant Description'.
  fieldcatalog-col_pos     = 34.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'KUNNR'.
  fieldcatalog-seltext_m   = 'Bill-to Customer'.
  fieldcatalog-col_pos     = 24.
  fieldcatalog-outputlen   = 15.
*  fieldcatalog-datatype     = 'CURR'.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'KUNNR_NAME1'.
  fieldcatalog-seltext_m   = 'Bill-to Description'.
  fieldcatalog-col_pos     = 25.
  fieldcatalog-emphasize   = 'X'.
  fieldcatalog-hotspot     = 'X'.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'NETWR'.
  fieldcatalog-seltext_m   = 'Invoice Total Dollar'.
  fieldcatalog-col_pos     = 26.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'ZZFLAG'.
  fieldcatalog-seltext_m   = 'Hold / Print Indicator'.
  fieldcatalog-col_pos     = 21.
*  fieldcatalog-checkbox = 'X'.
  fieldcatalog-edit = 'X'.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'ZZREASON'.
  fieldcatalog-seltext_m   = 'Reason Being Held'.
  fieldcatalog-col_pos     = 22.
  fieldcatalog-outputlen   = 15.
  fieldcatalog-edit = 'X'.
*  fieldcatalog-datatype     = 'CURR'.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'ZZUSER'.
  fieldcatalog-seltext_m   = 'Changed By'.
  fieldcatalog-col_pos     = 27.
*  fieldcatalog-edit = 'X'.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'ZZ_CHANGED_DATE'.
  fieldcatalog-seltext_m   = 'Changed Date'.
  fieldcatalog-col_pos     = 28.
*  fieldcatalog-edit = 'X'.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'ZZ_CHANGED_TIME'.
  fieldcatalog-seltext_m   = 'Changed Time'.
  fieldcatalog-col_pos     = 29.
*  fieldcatalog-edit = 'X'.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
  fieldcatalog-fieldname   = 'COUNT'.
  fieldcatalog-seltext_m   = 'Count'.
  fieldcatalog-col_pos     = 37.
  fieldcatalog-do_sum      = 'X'.
  fieldcatalog-no_zero     = 'X'.
  APPEND fieldcatalog TO fieldcatalog.
  CLEAR  fieldcatalog.
ENDFORM.                    " FIELD_CATALOG
*&      Form  user_command
*       text
*FORM user_command.
FORM user_command USING r_ucomm     LIKE sy-ucomm
                        rs_selfield TYPE slis_selfield.
  DATA: ltp_vbeln TYPE vbeln.  " Sales document number.
CASE  r_ucomm.
    WHEN '&IC1'.
      IF ( rs_selfield-fieldname = 'VBELN'
        OR rs_selfield-fieldname = 'BILL_VBELN' )
       AND rs_selfield-value IS NOT INITIAL.        " Display sales document.
        ltp_vbeln = rs_selfield-value.
        zcl_sales_doc=>display( ltp_vbeln ).
      ENDIF.
* Comments - r_ucomm = SEL is the Select All. I took out the perform show_report
* because that actually calls another screen with the new ALV, instead of replacing
* the existing ALV. I added the refresh/col_stable/row_stable = 'X' to achieve this
    WHEN 'SEL'.
      PERFORM update_itab_from_screen.
      LOOP AT it_extract2 INTO wa_extract.
        wa_extract-zzflag = 'X'.
        MODIFY it_extract2 FROM wa_extract.
      ENDLOOP.
      RS_SELFIELD-refresh = 'X'.
      RS_SELFIELD-col_stable = 'X'.
      RS_SELFIELD-row_stable = 'X'.
* Comments - r_ucomm = DSEL is the DeSelect All. I took out the perform show_report
* because that actually calls another screen with the new ALV, instead of replacing
* the existing ALV. I added the refresh/col_stable/row_stable = 'X' to achieve this
    WHEN 'DSEL'.
      PERFORM update_itab_from_screen.
      LOOP AT it_extract2 INTO wa_extract.
        CLEAR wa_extract-zzflag.
        MODIFY it_extract2 FROM wa_extract.
      ENDLOOP.
      RS_SELFIELD-refresh = 'X'.
      RS_SELFIELD-col_stable = 'X'.
      RS_SELFIELD-row_stable = 'X'..
* Comments - Insert your code to call VBRK updates here in the SAVE portion.
    WHEN 'PICK'.
*PERFORM update_itab_from_screen.
*     REFRESH it_msg.
* Upate vbrk append structure
  LOOP AT it_extract2 INTO wa_extract.
    w_idx2 = sy-tabix.
* if flag is on, there must be a reason
    if NOT wa_extract-zzflag is initial.
      if wa_extract-zzreason is initial.
        wa_msg-vbeln = wa_extract-vbeln.
        wa_msg-message =  'For Hold doc.,Reason required'(017).
        append wa_msg to it_msg.
        perform show_report.
        continue.
      endif.
    endif.
* only if the flag or reason has been changed with what's in database vbrk
* which was read in the beginning of program and stored in
* it_extract.
    read table it_extract into wa_extract3
      with key vbeln = wa_extract-vbeln.
    w_idx3 = sy-tabix.
    if sy-subrc = 0.
      if wa_extract3-zzflag <> wa_extract-zzflag
      or wa_extract3-zzreason <> wa_extract-zzreason.
        PERFORM update_vbrk.
      endif.
    endif.
   ENDLOOP.
      RS_SELFIELD-refresh = 'X'.
      RS_SELFIELD-col_stable = 'X'.
      RS_SELFIELD-row_stable = 'X'.
    WHEN 'EXIT'.
      LEAVE TO SCREEN 0.
* Comments - I would personally issue a message warning here instead of
* totally leaving the program.
    WHEN OTHERS.
      message w000(kx) with 'Inactive Key, Try Again'.
*     LEAVE TO SCREEN 0.
  ENDCASE.
ENDFORM.                    "user_command
*&      Form  top_of_page
*       text
FORM top_of_page.
*alv header declarations
  DATA: t_header TYPE slis_t_listheader,
       wa_header TYPE slis_listheader,
       t_line LIKE wa_header-info,
       ld_lines TYPE i,
       ld_linesc(10) TYPE c,
       i_logo TYPE c.
* Title
  wa_header-typ  = 'H'.
  wa_header-info = 'Print Confirmation Report'.
  APPEND wa_header TO t_header.
  CLEAR wa_header.
* Date
  wa_header-typ  = 'S'.
  wa_header-key = 'Date: '.
  CONCATENATE  sy-datum+6(2) '.'
               sy-datum+4(2) '.'
               sy-datum(4) INTO wa_header-info.   "todays date
  APPEND wa_header TO t_header.
  CLEAR: wa_header.
* Total No. of Records Selected
  DESCRIBE TABLE it_extract2 LINES ld_lines.
  ld_linesc = ld_lines.
  CONCATENATE 'Total No. of Records Selected: ' ld_linesc
                    INTO t_line SEPARATED BY space.
  wa_header-typ  = 'A'.
  wa_header-info = t_line.
  APPEND wa_header TO t_header.
  CLEAR: wa_header, t_line.
  CALL FUNCTION 'REUSE_ALV_COMMENTARY_WRITE'
    EXPORTING
      it_list_commentary = t_header.
      i_logo             = 'NEWALTA_LOGO'.
ENDFORM.                    "top_of_page
*                  SET PF STATUS FOR ALV                               *
* Comments - This is the form, similar to form USER_COMMAND, that is
* passed to your ALV function module so it knows where to grab the
* status from.
FORM set_pf_status USING rt_extab TYPE slis_t_extab.
  SET PF-STATUS 'STANDARD'.
ENDFORM.                    "set_pf_status
thanks

Answer 1

You need use the Function moduel in the user command.
GET_GLOBALS_FROM_SLVC_FULLSCR
follow the sample code.
REPORT ZTEST_ALV_CHECK MESSAGE-ID ZZ .
TYPE-POOLS: SLIS.
DATA: X_FIELDCAT TYPE SLIS_FIELDCAT_ALV,
IT_FIELDCAT TYPE SLIS_T_FIELDCAT_ALV,
L_LAYOUT TYPE SLIS_LAYOUT_ALV,
X_EVENTS TYPE SLIS_ALV_EVENT,
IT_EVENTS TYPE SLIS_T_EVENT.
DATA: BEGIN OF ITAB OCCURS 0,
VBELN LIKE VBAK-VBELN,
POSNR LIKE VBAP-POSNR,
CHK(1),
color(4),
END OF ITAB.
SELECT VBELN
POSNR
FROM VBAP
UP TO 20 ROWS
INTO TABLE ITAB.
X_FIELDCAT-FIELDNAME = 'CHK'.
X_FIELDCAT-TABNAME = 'ITAB'.
X_FIELDCAT-COL_POS = 1.
X_FIELDCAT-INPUT = 'X'.
X_FIELDCAT-EDIT = 'X'.
X_FIELDCAT-CHECKBOX = 'X'.
APPEND X_FIELDCAT TO IT_FIELDCAT.
CLEAR X_FIELDCAT.
X_FIELDCAT-FIELDNAME = 'VBELN'.
X_FIELDCAT-SELTEXT_L = 'VBELN'.
X_FIELDCAT-HOTSPOT = 'X'.
X_FIELDCAT-TABNAME = 'ITAB'.
X_FIELDCAT-COL_POS = 2.
APPEND X_FIELDCAT TO IT_FIELDCAT.
CLEAR X_FIELDCAT.
X_FIELDCAT-FIELDNAME = 'POSNR'.
X_FIELDCAT-SELTEXT_L = 'POSNR'.
X_FIELDCAT-TABNAME = 'ITAB'.
X_FIELDCAT-COL_POS = 3.
APPEND X_FIELDCAT TO IT_FIELDCAT.
CLEAR X_FIELDCAT.
L_LAYOUT-info_fieldname = 'COLOR'.
*L_LAYOUT-ZEBRA = 'X'.
CALL FUNCTION 'REUSE_ALV_GRID_DISPLAY'
EXPORTING
I_CALLBACK_PROGRAM = SY-REPID
IS_LAYOUT = L_LAYOUT
I_CALLBACK_PF_STATUS_SET = 'STATUS'
I_CALLBACK_USER_COMMAND = 'USER_COMMAND'
IT_FIELDCAT = IT_FIELDCAT
TABLES
T_OUTTAB = ITAB
EXCEPTIONS
PROGRAM_ERROR = 1
OTHERS = 2.
IF SY-SUBRC 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.
*& Form STATUS
text
-->P_EXTAB text
FORM STATUS USING P_EXTAB TYPE SLIS_T_EXTAB.
Pf status
SET PF-STATUS 'STATUS'.
ENDFORM. " STATUS
*& Form USER_COMMAND
text
-->R_UCOMM text
-->RS_SELFIELD text
FORM USER_COMMAND USING R_UCOMM LIKE SY-UCOMM
RS_SELFIELD TYPE SLIS_SELFIELD.
DATA: GD_REPID LIKE SY-REPID, "Exists
REF_GRID TYPE REF TO CL_GUI_ALV_GRID.
IF REF_GRID IS INITIAL.
CALL FUNCTION 'GET_GLOBALS_FROM_SLVC_FULLSCR'
IMPORTING
E_GRID = REF_GRID.
ENDIF.
IF NOT REF_GRID IS INITIAL.
CALL METHOD REF_GRID->CHECK_CHANGED_DATA .
ENDIF.
loop at itab where chk = 'X'.
itab-color = 'C300'.
modify itab index sy-tabix transporting color.
endloop.
RS_SELFIELD-refresh = 'X'.
break-point.
ENDFORM. "USER_COMMAND