foreign key question

Hi folks,

I have a table which lists facilities and another table that lists access
levels for those facilities. All straight forward using a foreign key set up
using a normal references clause.

users=# select f_id, f_desc from facilities order by f_id;
f_id | f_desc
------+---------------------
1 | Login
3 | Users
....
16 | Itinerary
....
31 rows)

users=# select * from facility_levels ;
fl_f_id | fl_level | fl_desc
---------+----------+-----------------------
16 | 1 | Own itinerary
16 | 2 | Dealer/Dept itinerary
16 | 3 | Dept itinerary
16 | 4 | Dealer/Dept On/Off
16 | 5 | Dept On/Off
16 | 6 | All On/Off
16 | 7 | All features
(7 rows)

users=#

Now I want to set up a new access level table specific to the itinerary, along
the lines of

u_id int4 not null references users(u_id)
fl_level int4 not null references facility_levels(16, fl_level)

Firstly, is this possible, and secondly how would I do it?
--
Gary Stainburn
I.T. Manager
Ringways Garages
http://www.ringways.co.uk