How would I write this query...

Hi -

  I have two tables, one of them has names of people and an associated
integer ID.  The other table is a list of the people (from the first table)
by their ID number that have signed up for a class.  How would I write a
query that would list all the people from the first table that do not have
any entries in the second table?   Basically, I want a listing of all my
people who have not signed up for the class.

Thanks!
-Jim