Add User command functionality to ALVgrid report


In order to add user command functioality to the ALV grid you need to perform the following steps:
    	           1. Update 'REUSE_ALV_GRID_DISPLAY' FM call to include 'USER_COMMAND' FORM
	           2. Create 'USER_COMMAND' FORM


 call function 'REUSE_ALV_GRID_DISPLAY'
       exporting
            i_callback_program      = gd_repid
            i_callback_top_of_page   = 'TOP-OF-PAGE'
            I_callback_user_command = 'USER_COMMAND'   "see FORM 
            is_layout               = gd_layout
            it_fieldcat             = fieldcatalog[]
            i_save                  = 'X'
       tables
            t_outtab                = it_ekko
       exceptions
            program_error           = 1
            others                  = 2.

*------------------------------------------------------------------*
*       FORM USER_COMMAND                                          *
*------------------------------------------------------------------*
*       --> R_UCOMM                                                *
*       --> RS_SELFIELD                                            *
*------------------------------------------------------------------*
FORM user_command USING r_ucomm LIKE sy-ucomm
                  rs_selfield TYPE slis_selfield.

* Check function code
  CASE r_ucomm.
    WHEN '&IC1'.
*   Check field clicked on within ALVgrid report
    IF rs_selfield-fieldname = 'EBELN'.
*     Read data table, using index of row user clicked on
      READ TABLE it_ekko INTO wa_ekko INDEX rs_selfield-tabindex.
*     Set parameter ID for transaction screen field
      SET PARAMETER ID 'BES' FIELD wa_ekko-ebeln.
*     Sxecute transaction ME23N, and skip initial data entry screen
      CALL TRANSACTION 'ME23N' AND SKIP FIRST SCREEN.
    ENDIF.
  ENDCASE.
ENDFORM.