lighttpd and dirs with with mod_auth

I have a "little" problem with my lighttpd server, reaching over squid
web proxy.
When I configure browser, to use proxy, I couldʼn't enter username and
password for mod_auth secured directorys. I directly get a "Not
authenticated" error.
What do I need to configure in squid.conf to such a folder correctly?

Another problem is, that facebook chat didʼn't work with use of a squid
web cache proxy. Need help there too, to configure squid correctly.

Greetz

Kromonos