[squid-users] squid cache tuning questions

hi, squid-users!

i have the squid 2.4-STABLE6 on my proxy server, and i very want reduce
consuption of traffic.

how i configure squid to release the following algorithm?

1. user try to download something (let it http://www.some-server.com/test.html)
from proxy (my squid).
2. squid must see to his own cache to hear size, date and time of cached test.html.
3. now squid looks to real http://www.some-server.com/test.html to hear his
size, date and time.
4. if first and second size, date or time different, only then squid will
download this real file, store in his cache and transfer it to user.
5. of course if file not exist in cache, then squid immediately downloads the
file.

i.e. i want make to my squid will ignore all "no-cache" and other http
attributes, and will use only this algorithm.

it is possible? if not, how i can reduce consuption of traffic by tuning squid
with action like this algorithm?

ps. or i'm full stupid, that thing this algorithm?

-- 
Dmitry Suhodoev, http://www.bingo.ru/, icq#550315