Detect Button onRollOver

I have a flash app that loads and displays swfs (converted from PDFs ). Any link/url within a PDF is displayed as a Button when converted to a swf. So I have loads of Buttons in my app nested in the swfs and no way to reference them as I don't no the instance names.

Is there some way of detecting when I rollover a Button (any button) so I can attach a function.
e.g