INCLUDE STRUCTURE ?

hi there,

i have an internal table:

DATA: BEGIN OF gt_alv_out OCCURS 100.
        INCLUDE STRUCTURE zzfl_fehler_prot.
*        chk(1) type c. 
DATA: END OF gt_alv_out.

well, i want to add the field chk to the internal table. but this is not working.

i can NOT add the field to the structure zzfl_fehler_prot.

how to handle this ?

reg, Martin