exiting with badarg

[lyn]

I'm trying to diagnose an error message and I wonder if
anything immediately jumps out at the experts.  here is the
shell interaction:

55> chat_client:signup(). 
** exited: {badarg,{chat_client,signup,[]}} **

=ERROR REPORT==== 12-Jun-1999::23:29:29 ===
!!! Error in process <0.144.0> with exit value: 
{badarg,{chat_client,signup,[]}}

I assume this means that chat_client doesn't contain a zero
argument function called signup.  But chat_client.erl contains this:


signup() ->
    chat_server ! {sign_up, name(), self()},
    receive {ok, Pid} ->
        io:format("signup succeeded"),
	    chat_client_dispatch(name())
    after 5 ->
        failed
    end.

so where is this bad match occurring?  


thanks,
-Lyn