[erlang-questions] Help - Can I stop this warning?

[G Bulmer]

I have been playing with this macro to print the current functions name:

-define(IOFUN(), io:format("~s: ", [case process_info(self 
(),current_function) of {_,{_,F,_}} ->F end])).

Unfortunately, I get this irritating warning on *every* function, on  
the first use of ?IOFUN():
./script.erl:34: Warning: variable 'F' exported from 'case' (line 31)
...

Can someone suggest how I get rid of it?

Garry