Attachment fu file path

Hi I am using attachment fu plugin for uploading data.

say : User has_many :photos

I wanted to save the uploaded photo in the path as follows.

/files/<user_id>/photos/1.jpg - while uploading first photo /files/<user_id>/photos/2.jpg - while uploading second photo

1) Is there any way to make a folder name with user id ? 2) Is there any way to rename the file in sequential order ?

Thanks in advance, srikanth