Not triggering PBO in OOABAP ALV grid

Question

Hi all.
I want to create drop down for Document type BSART.for that iam using OOABAP but my program is not triggering PBO module itself.I have seen so many examples but iam unable to fetch data.what are the changes i have to do here.i have reduced some code here.i have written my final internal table select query before this stataement.
loop at it_git_final into wa_git_final.
APPEND wa_git_final TO it_git_final.
ENDLOOP.
*Call to ALV
  CALL SCREEN 600.
MODULE status_0600 OUTPUT.
SET PF-STATUS 'DISP'.
SET TITLEBAR 'ALVF4'.
ENDMODULE.                 " STATUS_0600  OUTPUT
calling the PBO module ALV_GRID.
MODULE pbo OUTPUT.
*Creating objects of the container
  *  SET field for ALV
  if g_custom_container is initial.
  perform create_and_init_alv changing it_git_final
                                         gt_fieldcat.
PERFORM alv_build_fieldcat.
  endif.
  * Set ALV attributes FOR LAYOUT
PERFORM alv_report_layout.
   CHECK NOT c_alvgd IS INITIAL.
Call ALV GRID
   CALL METHOD c_alvgd->set_table_for_first_display
    EXPORTING
      is_layout                     = it_layout
      i_save                        = 'A'
    CHANGING
      it_outtab                     = it_git_final
      it_fieldcatalog               = it_fcat
    EXCEPTIONS
      invalid_parameter_combination = 1
      program_error                 = 2
      too_many_lines                = 3
      OTHERS                        = 4.
  IF sy-subrc <> 0.
    MESSAGE ID sy-msgid TYPE sy-msgty NUMBER sy-msgno
               WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.
  ENDIF.
   ENDMODULE.                 " PBO  OUTPUT
      MODULE PAI INPUT                                              *
MODULE pai INPUT.
   ENDMODULE.                    "pai INPUT
*subroutine to build fieldcat
FORM alv_build_fieldcat changing pt_fieldcat type lvc_t_fcat..
   DATA lx_fcat TYPE lvc_s_fcat.
  CALL FUNCTION 'LVC_FIELDCATALOG_MERGE'
    EXPORTING
      i_structure_name = 'IT_GIT_FINAL'
    CHANGING
      ct_fieldcat      = gt_fieldcat.
* To assign dropdown in the fieldcataogue
LOOP AT gt_fieldcat INTO lx_fcat.
   DATA : lx_fcat TYPE lvc_s_fcat.
  lx_fcat-row_pos   = '1'.
  lx_fcat-col_pos   = '1'.
lx_fcat-fieldname = 'CHECK1'.
lx_fcat-ref_field = 'CHECK1'
  lx_fcat-EDIT = 'X'.
  lx_fcat-coltext = 'Check Box'.
lx_fcat-seltext = text-c01.
APPEND lx_fcat TO Gt_fieldcat.
CLEAR lx_fcat.
lx_fcat-row_pos   = '1'.
  lx_fcat-col_pos   = '15'.
  lx_fcat-fieldname = 'BSART'.
  lx_fcat-ref_field = 'BSART'.
  lx_fcat-ref_table = 'T161P'.
  lx_fcat-coltext = 'Document Type'.
lx_fcat-drdn_hndl = '1'.
  lx_fcat-outputlen = 15.
  lx_fcat-edit = 'X'.
  append  lx_fcat to gt_fieldcat.
  CLEAR lx_fcat.
   DATA: lt_dropdown TYPE lvc_t_drop,
        ls_dropdown TYPE lvc_s_drop.
  ls_dropdown-handle = '1'.
  ls_dropdown-value = '01 ZFC Vesselchart Contract'.
  APPEND ls_dropdown TO lt_dropdown.
  ls_dropdown-handle = '1'.
  ls_dropdown-value = '02 ZQTY QTY Contract(SESA)'.
  APPEND ls_dropdown TO lt_dropdown.   ls_dropdown-handle = '1'.
*method to display the dropdown in ALV
  CALL METHOD g_grid->set_drop_down_table
    EXPORTING
      it_drop_down = lt_dropdown.
LOOP AT it_fcat INTO lx_fcat.
    CASE lx_fcat-fieldname.
To assign dropdown in the fieldcataogue
      WHEN 'BSART'.
        lx_fcat-drdn_hndl = '1'.
        lx_fcat-outputlen = 15.
        MODIFY it_fcat FROM lx_fcat.
    ENDCASE.
  ENDLOOP.
      endform.
form ALV_OUTPUT .
*Create object for container
CREATE OBJECT g_custom_container
        EXPORTING container_name = 'CCONT'.
*create object for grid
CREATE OBJECT g_grid
        EXPORTING i_parent = g_custom_container.
  CALL METHOD g_grid->set_table_for_first_display
    EXPORTING
      is_layout       = it_layout
    CHANGING
      it_fieldcatalog = gt_fieldcat
      it_outtab       = it_git_final.
endform.                    " ALV_OUTPUT
form ALV_REPORT_LAYOUT .
  it_layout-cwidth_opt = 'X'.
  it_layout-col_opt = 'X'.
  it_layout-zebra = 'X'.
endform.                    " ALV_REPORT_LAYOUT
form CREATE_AND_INIT_ALV  changing p_it_git_final
                                   p_gt_fieldcat.
  create object g_custom_container
         exporting container_name = g_container.
  create object g_grid
         exporting i_parent = g_custom_container.
endform.

Answer 1

Hello Raj
  Actually all the code is described in PBO module, so you need to invoke this module in PBO when defining the screen.
For example, access transaction SE51, start in Change mode and inser line
    MODULE PBO.
Then activate the object
Best regards
Carlos Machad o