Proxy Authentication

Hi there,

        Haveing a few probs with this one....I don't seem to be able to
get the password box to apear !

Heres some stuff from my squid.conf that will probably have half of
you saying that i can't write an ACL !!!

The problem comes in trying to restrict it on an IP address rather
than a user....I've tried all sorts of different things, but no joy !

The ncsa authntication works, the password file is correct and i
can make changes via the chpasswd.cgi script

--
authenticate_program /usr/local/squid/bin/ncsa_auth 
/usr/local/squid/etc/passwd
acl metro-restrict src 10.1.1.230/255.255.255.255
acl metro_restrict proxy_auth REQUIRED
http_access allow metro-restrict	
----
Any ideas ???
Thanks,
			Lee