'Backwards' compatibility with Flash Paper

[seanonymous]

If have a product that is currently using Flash Paper documents, but I want to (gradually) start replacing them with Print2Flash docs, what is the best way for my code to tell the difference between a Flash Paper document and a Print2Flash document?

Just to clarify:

1. I load a swf into my AS2 project
2. The swf might be Flash Paper, it might be Print2Flash
3. My project identifies which type of document it is by checking … ???
4. My project addresses the API properly based on the step above

Thanks!