Thank you for reply. I make it first: handle_event({test}, State) -> io:format("Test"), {ok, State}; handle_event(_Event, _State) -> {ok, _State}. But when i call notify/1 it's nothing output. -- View this message in context: http://erlang.2086793.n4.nabble.com/gen-event-help-tp3242753p3243763.html Sent from the Erlang Questions mailing list archive at Nabble.com.