[GENERAL] how to call a stored function from another stored function? even possible?

[Java Services]

I have a stored functionA that returns void

Inside there I have a line that says:
   select functionB();

and it gives this error.

ERROR:  query has no destination for result data
HINT:  If you want to discard the results of a SELECT, use PERFORM instead.
CONTEXT:  PL/pgSQL function "functionA" line 13 at SQL statement

********** Error **********


any ideas?