Select all and Deselect all icons not working for check boxes in alv list display

Select all and Deselect all functionality is not working. Remaining Icons are working.  I put a break point in Form ALV_STATUS.

When click on Select all or Deselect all icons nothing is happening. Sort icons are working.

This is a lower version of sap. So no oops please.

types : begin of ty_final,

         flag(1) type c,

         vbeln like likp-vbeln,        "Delivery

         lfdat like likp-lfdat,        "Delivery date

         verur like likp-verur,        "Identification

data : t_final type table of ty_final,

        wa_final like line of t_final.

form build_fcat.

  wa_fcat-col_pos = '01'.

  wa_fcat-fieldname = 'FLAG'.

  wa_fcat-tabname = 'T_FINAL'.

  wa_fcat-seltext_l = 'Check'.

  wa_fcat-outputlen = '2'.

  wa_fcat-checkbox = 'X'.

  wa_fcat-input = 'X'.

  wa_fcat-key = 'X'.

  append wa_fcat to t_fcat.

  clear wa_fcat.

form alv_status using extab type slis_t_extab.

   set pf-status 'ZSTATUS'.

endform.                               " ALV_STATUS

form display_alv_grid.

  call function 'REUSE_ALV_LIST_DISPLAY'

      exporting

         i_callback_program       = 'ZREPORT'

         i_callback_pf_status_set = 'ALV_STATUS'

         i_callback_user_command  = 'USER_COMMAND'

Please help me.