Always save when closing any preexisting file without a prompt

Is it possible to do that? Something like "autosave when closing".

I think you are seeking the "Save and Close" command. For more convenience, you can: - Give it a shortcut key; - Make a toolbar button for it; (The default macros are good examples.) - Put it into a menu. By the way, use "Keyboard Map" (e.g. type "close save" in it) and you can find more by yourself.