JQuery :: Autocomplete Trigger Event If User Rejects All Autocomplete Options

Does anyone have a library or patch to call a handler if a user leaves an autocomplete field without choosing one of the autocomplete options - i.e. they've entered free text. I'm working with an app that populates multiple fields from a single auto-complete value, and our latest requirement is to clear out a bunch of fields if the user's entered something manually - rejecting autocomplete suggestions. My initial attempts at hooking into onkeyfoo and onblur haven't lead anywhere productive, and I'm hoping someone else has managed to overcome the gnarly event and timing dependencies involved with onkeyfoo and blur being used for standard autocomplete behaviour.