User based acl's - again

Hi,
Sorry to bring this up again, but after some advice last time I thought I could
work it out. So are the following acl's access rules valid?

acl Year11 proxy_auth "/etc/squid/etc/yr11"
 
then in the http_access rules

http_access deny Year11

The "/etc/squid/etc/yr11" file is a list if usernames one per line - and only the
username (no password or other visible character).

--
Simon Bryan                    sbryan@olmc.nsw.edu.au
Information Technology Manager sbryan@mpx.com.au
OLMC Parramatta