terminate child under simple one for one supervisor

[Thilani Abeysinghe]

hi,
I have created following supervision tree.

Sup1(one for all)  Under Sup1 there is Sup2(simple one for one)  and a
gen_server Gen1(gen_server).
Under Sup2(simple one for one) there is another gen_server.
Gen2(gen_server).

child is added by Gen1 calling supervisor:start_child(_,_)

Gen2 starting successfuly.
I want to know is there a way to stop the Gen2 gen_server.
tried to use
supervisor:terminate_child(SupRef, Id)
it returned  {error,simple_one_for_one}


~Thilani Abeysinghe