[Zope] Deleting a file in Python

I'm reading the zope book, 2.6. And I've worked through the ZopeZoo tutorial in chapter 11. I want to make it possible to delete entries in the GuestBook via its web interface. It uses a python script to create the file with the line: context.manage_addProduct['OFSP'].manage_addFile(id, title="", file=comments) I assume I could write something like: context.manage_deleteProduct['OFSP'].manage_removeFile(id) or maybe: context.manage_addProduct['OFSP'].manage_deleteFile(id) but I can't figure out where context.* is documented.