Back, cancel and exit - disabled problem!!!

Question

hi,
please find the code of my program below. it is working fine but i am not able to make the back, exit and cancel button in the standard toolbar(buttons beside the box where we write the trascaction code) enabled. can any one tell me how to make those buttons enabled???
thanks in advance,
pushpa
tables kna1.
data: begin of itkna1 occurs 0,
         ktokd like kna1-ktokd,
         kunnr like kna1-kunnr,
         name1 like kna1-name1,
         name2 like kna1-name2,
         ktokd_hdl type int4,
      end of itkna1.
*creating an instance of grid
data it_custom_control_name type scrfname value 'C_C_ALV'.  "custom control name
data it_container type ref to cl_gui_custom_container.      "container
data it_alvgrid type ref to cl_gui_alv_grid.                "grid control
data it_lyo type lvc_s_layo.                                "layout internal table
data it_fcat type lvc_t_fcat.                               "fieldcatagory internal table
data it_hype type lvc_t_hype.                               "hyperlink internal table
data tmp_hype type lvc_s_hype.                              "temp hyperlink internal table
data gs_toolbar type stb_button.                            "toolbar instance
data ok_code like sy-ucomm.
data gt_hypetab type lvc_t_hype.
data ls_hype type lvc_s_hype.
ls_hype-handle = '1'.
ls_hype-href = 'http://www.sap.com'.
append ls_hype to gt_hypetab.
ls_hype-handle = '2'.
ls_hype-href = 'http://www.yahoo.com'.
append ls_hype to gt_hypetab.
ls_hype-handle = '3'.
ls_hype-href = 'http://www.gmail.com'.
append ls_hype to gt_hypetab.
ls_hype-handle = '4'.
ls_hype-href = 'http://www.orkut.com'.
append ls_hype to gt_hypetab.
ls_hype-handle = '5'.
ls_hype-href = 'http://www.rediffmail.com'.
append ls_hype to gt_hypetab.
ls_hype-handle = '6'.
ls_hype-href = 'http://www.hotmail.com'.
append ls_hype to gt_hypetab.
ls_hype-handle = '7'.
ls_hype-href = 'http://www.deals2buy.com'.
append ls_hype to gt_hypetab.
*class lcl_event_receiver definition
class lcl_event_receiver definition.
  public section.
  methods handle_toolbar_set
    for event toolbar of cl_gui_alv_grid
    importing e_object e_interactive.
  methods handle_double_click
   for event double_click of cl_gui_alv_grid
   importing e_row e_column.
  methods handle_user_command
   for event user_command of cl_gui_alv_grid
   importing e_ucomm sender.
  methods handle_hotspot_click
    for event hotspot_click of cl_gui_alv_grid
    importing e_row_id e_column_id es_row_no.
  private section.
  data i type i.
endclass.
data event_receiver type ref to lcl_event_receiver.
*creating screen to enter selection  criteria
selection-screen begin of block enter_data with frame title text-001.
  parameters pktokd like kna1-ktokd obligatory.
  select-options skunnr for kna1-kunnr.
selection-screen end of block enter_data.
*copying the data from the database table to the internal table
select ktokd kunnr name1 name2
  from kna1 into corresponding fields of table itkna1
       where ktokd = pktokd and kunnr in skunnr.
*prepare field catalog
perform prepare_fieldcat using:
1 'KTOKD' 'KNA1'  8  '' 'KTOKD_HDL' it_fcat,
2 'KUNNR' 'KNA1' 10 'X' '' it_fcat,
3 'NAME1' 'KNA1' 15  '' '' it_fcat,
4 'NAME2' 'KNA1' 15  '' '' it_fcat.
*loop at itkna1.
itkna1-ktokd_hdl = sy-tabix."gt_hypetab-handle.
*ENDLOOP.
*modify itkna1.
*prepare layout
it_lyo-grid_title = 'Custormer details'.
call screen 200.
module status_0200 output.
set pf-status 'MAIN100'.
set titlebar 'MAIN100'.
*creating an instance of container class
create object it_container
    exporting container_name = it_custom_control_name.
*creating an instance of the grid
create object it_alvgrid
    exporting i_parent = it_container.
create object event_receiver.
set handler event_receiver->handle_toolbar_set for it_alvgrid.
set handler event_receiver->handle_double_click for it_alvgrid.
set handler event_receiver->handle_user_command for it_alvgrid.
set handler event_receiver->handle_hotspot_click for it_alvgrid.
*displaying the grid
call method it_alvgrid->set_table_for_first_display
   exporting
     is_layout = it_lyo
     "it_hyperlink = it_hype
     it_hyperlink = gt_hypetab
   changing
     it_outtab = itkna1[]
     it_fieldcatalog = it_fcat
   exceptions
     invalid_parameter_combination = 1
     others = 2.
endmodule.
*class definition for hotspot click
class lcl_event_receiver implementation.
  method handle_hotspot_click.
    data t_d1 like line of itkna1.
    read table itkna1 into t_d1 index es_row_no-row_id.
    set parameter id 'KUN' field t_d1-kunnr.
    call transaction 'XD03' and skip first screen.
  endmethod.
  method handle_user_command.
    case e_ucomm.
      when 'REFR'.
        perform refresh.
      when 'TOOLBAR'.
        call method sender->set_toolbar_interactive.
     endcase.
  endmethod.
  method handle_double_click.
message i000(0k) with 'Zeile'(010) e_row 'SpaltenID'(002) e_column.
    message 'double click' type 'S'.
    call method cl_gui_control=>set_focus
      exporting control = it_alvgrid.
  endmethod.
method handle_toolbar_set.
  clear gs_toolbar.
  move 'DELE' to gs_toolbar-function.
  move icon_delete to gs_toolbar-icon.
  move 'Mein Löschen'(111) to gs_toolbar-quickinfo.
  move ' ' to gs_toolbar-disabled.
  append gs_toolbar to e_object->mt_toolbar.
  clear gs_toolbar.
  move 'REFR' to gs_toolbar-function.
  move icon_refresh to gs_toolbar-icon.
  move 'Mein Refresh'(112) to gs_toolbar-quickinfo.
  move ' ' to gs_toolbar-disabled.
  insert gs_toolbar into e_object->mt_toolbar index 1.
*del  APPEND GS_TOOLBAR TO E_OBJECT->MT_TOOLBAR.
  clear gs_toolbar.
  move 'MBUT' to gs_toolbar-function.
  move icon_checked to gs_toolbar-icon.
  move 'My Menubutton'(101) to gs_toolbar-quickinfo.
  move 2 to gs_toolbar-butn_type.
  move space to gs_toolbar-disabled.
  append gs_toolbar to e_object->mt_toolbar.
  clear gs_toolbar.
  move 'MBUT1' to gs_toolbar-function.
  move icon_cancel to gs_toolbar-icon.
  move 'My Menubutton disabled'(102) to gs_toolbar-quickinfo.
  move 2 to gs_toolbar-butn_type.
  move 'X' to gs_toolbar-disabled.
  append gs_toolbar to e_object->mt_toolbar.
  call method cl_gui_control=>set_focus
    exporting control = it_alvgrid.
endmethod.
endclass.
module user_command_0200.
  case ok_code.
    when 'BACK'.
      perform exit_program.
    when 'EXIT'.
      perform exit_program.
    when 'CANCEL'.
      perform cancel.
    when 'REFRESH'.
      perform refresh_table.
  endcase.
endmodule.
*module to perform cancel function to cancel the action
form cancel.
endform.
*module to refresh the screen
form refresh.
message 'REFRESH' type 'S'.
endform.
*module to make the exit button on the toolbar to exit
form exit_program.
  call method it_container->free.
  set screen 0.
  leave screen.
endform.
*module to refresh the internal table after a modification is made
form refresh_table.
  message 'refresh table' type 'S'.
endform.
*filling the field catalog internal table
form prepare_fieldcat using pos p_fname p_tabname len p_hspot p_hdl t_fcat type lvc_t_fcat..
data tmp_fcat like line of it_fcat.
clear tmp_fcat.
tmp_fcat-fieldname = tmp_fcat-ref_field = p_fname.
tmp_fcat-ref_table = p_tabname.
tmp_fcat-outputlen = len.
tmp_fcat-col_pos = pos.
tmp_fcat-hotspot = p_hspot.
tmp_fcat-web_field = p_hdl.
append tmp_fcat to it_fcat.
endform.

Answer 1

did you use pf-status in ur program,if so click on pf-status ,then use BACK,EXIT,CANC all are should be Upper case