Hi all, This is probably an obvious question: all the sample codes do quit() in a GuiState like this: @Override public void quit() { super.quit(); if (frame != null) { frame .dispose(); } } I was just curious if the null check is required here. I don't see when the frame can be null, could you help me with that? It is always initialized properly in init() and quit() cannot be called without initializing the GuiState, right? Thanks for the clarification in advance! Best, Richard -- Richard O. Legendi Software developer Intelligent Applications and Web Services AITIA International, Inc. http://people.inf.elte.hu/legendi/