attachment_fu

Hi,

Does anyone know how to use attachment_fu to upload a file to a folder
that is chosen dynamically?
i know you can use :path_prefix but this puts all the files in the
same folder.
I really want the user to choose which folder to upload the file into
each time. But I cannot work out how to do it.

Can anyone point me in the right direction?

Cheers,

Tim Fernandez