ya thanks avin. i think to begin with i got a centos rhl wich i use as a proxy server then from thatone there are several users in the house like three in the siting room then other 5 beds got other computer all the other computers are using windows xp except for the proxy that got linux. the problem now here is i dont need the bedrooms to access the internet using my proxy. so i went on to the file squid and make this rule
{our_networks = src xxx.xxx.xx.0/3"
allow our_networks}
where the x:=digits of my ip address and 1 to 3 are the ip addresses of my three machines i wanna allow.
in this case mr centos in the file squid whenever i started it it returns an error which is like "ip address out of range....................."
and the blacklisted machines still access the network. if there is the need for more specific details please jus make me know.