ACL Control , http access

I have created an acl list

acl privilege_ip src 192.168.0.1/255.255.255.0
acl all 192.168.0.0/255.255.255.0

http_access allow privilege_ip
htpp_access deny all

Squid allows all the ip's on the network to browse it has to be allow only the 
ip 192.168.0.1 but it doesn't. and it doesn't read the next line, it is having 
a match at first line

It is interpreting the first line like
allow all ip addresses.

Can anybody help me on the same how can I resolve this problem. I only want to 
allow specific ip's to browse and others should not. Help is needed on urgent 
basis.

Thanks & Regards,

Saif Ali Khan
Feditec (Pvt.) Ltd.