Not able to display the result,getting short dump error "GETWA_NOT_ASSIGNED".

TYPE-POOLs : slis.


data : BEGIN OF itab OCCURS 0,
         connid TYPE sflight-connid,
        carrid type sflight-carrid,
         fldate TYPE sflight-fldate,
          price TYPE sflight-price,
           currency TYPE sflight-currency,
           planetype TYPE sflight-planetype,
   END OF itab.




DATA : i_fcat TYPE slis_t_fieldcat_alv,
        wa_fcat type slis_fieldcat_alv,
        prg TYPE sy-repid VALUE sy-repid.

SELECT  connid carrid fldate price currency planetype
   from sflight INTO TABLE itab.

wa_fcat-tabname = 'ITAB'.
wa_fcat-col_pos = '1'.
wa_fcat-fieldname = 'CONNID'.

APPEND wa_fcat to i_fcat.
CLEAR wa_fcat.
wa_fcat-tabname = 'ITAB'.
wa_fcat-col_pos = '2'.
wa_fcat-fieldname = 'CARRID'.

APPEND wa_fcat to i_fcat.
CLEAR wa_fcat.

wa_fcat-tabname = 'ITAB'.
wa_fcat-col_pos = '3'.
wa_fcat-fieldname = 'FLDATE'.

APPEND wa_fcat to i_fcat.
CLEAR wa_fcat.

wa_fcat-tabname = 'ITAB'.
wa_fcat-col_pos = '4'.
wa_fcat-fieldname = 'PRICE'.

APPEND wa_fcat to i_fcat.
CLEAR wa_fcat.

wa_fcat-tabname = 'ITAB'.
wa_fcat-fieldname = 'CURRENCY'.

wa_fcat-no_out = 'x'.
APPEND wa_fcat to i_fcat.
CLEAR wa_fcat.

wa_fcat-tabname = 'ITAB'.
wa_fcat-fieldname = 'PLANETYPE'.

wa_fcat-no_out = 'x'.
APPEND wa_fcat to i_fcat.
CLEAR wa_fcat.



CALL FUNCTION 'REUSE_ALV_LIST_DISPLAY'
  EXPORTING
     I_CALLBACK_PROGRAM             = sy-cprog

    I_STRUCTURE_NAME               = 'SFLIGHT'

    IT_FIELDCAT                    = i_fcat

   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.
ENDIF.