MySQL + PHP: fetching data using foreign keys

Question

I have 2 tables (Users, Wall). The UserID in the Wall table is a foreign key. How would I go about fetching the users details using this? (I want to fetch the users Forename

Answer 1

Or in an alternative form:

SELECT w.*, u.Forename, u.Surname
FROM Wall w, Users u
WHERE w.UserID=u.UserID