How to determine the functional dependencies

I am to create a logical data model based on my own project specification and also determine the functional dependencies.

Table User example data:

user_id username    regDate          type subscription
      1    JohnS 01-01-2012 Administrator         NULL
      2   PeterB 02-01-2012     Moderator       Movies
      3   PeterA 02-01-2012          User       Movies
      4     Gary 03-01-2012          User        Books
      5    Irene 03-01-2012          User       Movies
      6     Stan 03-01-2012          User       Movies
      7    Isaac 04-01-2012          User        Books

Primary key: user_id
Unique key: username
Foreign key: subscription

How do I determine the functional dependencies?

I get two functional dependencies:
user_id -> username, regDate, type, subscription
username -> user_id, regDate, type, subscription