[Zope] Any examples of use of manage_addFile()?

I want to create a user-interface so that users can upload files to my Zope site. I have done this with DTMLDocuments, however I don't quite understand how to get the file itself into the Zope site via ... self.manage_addProduct['OFSP'].manage_addFile() ..that is in Python. I looked through the HOWTO's but didn't find anything. Does someone have an example of a Form/DTMLMethod/Python script that does this sort of thing? Thanks in advance, Ron ./.