[Ask] Blok all situs just allow web tertentu saja

[init-z]

Code:

acl backoffice src 10.33.17.0/24
# RFC1918 possible internal network
acl backoffice src 172.182.70.0/24 172.182.71.222/32 172.182.71.228/32 172.182.71.243-172.182.71.244/32 172.182.71.246-172.182.71.247/32 172.182.71.249/32 172.182.72.40/32 172.182.72.228-172.182.72.235/32 172.182.72.245/32 172.182.72.225/32 172.182.72.43/32
# RFC1918 possible internal network
acl backoffice src 192.168.83.0/24 # RFC1918 possible internal network
acl agent src 172.182.72.0/24 192.168.18.3/32
acl local dst 192.168.18.0/24 172.182.0.0/16
acl download url_regex -i \.exe$ \.mp3$ \.mp4$ \.tar.gz$ \.gz$ \.zip$
acl download url_regex -i \.tar.bz2$ \.rpm$ \.zip$ \.rar$ \.avi$ \.mpg$ \.mpeg$ \.rm$ \.iso$ \.wav$ \.dat$
acl download url_regex -i \.mov$ \.dat$ \.mpe$ \.mid$ \.midi$ \.rmi$ \.wma$ \.wmv$ \.ogg$ \.ogm$
acl download url_regex -i \.m1v$ \.mp2$ \.mpa$ \.wax$ \.m3u$ \.asx$ \.wpl$ \.wmx$ \.dvr-ms$ \.snd$ \.mp4$ \.mkv$
acl download url_regex -i \.au$ \.aif$ \.asf$ \.m2v$ \.m2p$ \.ts$ \.tp$ \.trp$ \.div$ \.divx$ \.msi$
acl download url_regex -i \.mod$ \.vob$ \.aob$ \.dts$ \.ac3$ \.cda$ \.vro$ \.deb$ \.flv$ \.jar$

acl restdomain url_regex "/etc/squid/list/domain.txt"
http_access deny restdomain all
acl restkata url_regex -i "/etc/squid/list/kata.txt"
http_access deny restkata all
acl youtube dstdomain -i .youtube.com .4shared.com .jango.com
acl striming url_regex -i get_video\?video_id videodownload\?
acl strime url_regex -i watch?
#cache_object allow youtube
#cache_object allow striming
#cache_object allow strime
http_access allow all backoffice
# And finally deny all other access to this proxy
#http_access allow localhost
http_access deny all

gan,, saya punya config squid seperti diatas..
tapi skrang saya mau rubah supaya hanya bisa membuka web tertentu saja (mis: yahoomail, gmail)
gimana yah untuk acl nya..

terimakasih sebelumnya.