Squid, Dansguardian, Debian and IPTables...

Hello everyone im quite new to linux and i was tasked to create a content filter for our school, based on my research i found squid and dansguardian a good combo so i gave it a try, the proxy works but the filtering wont work... can someone please help me, here is my config

squid 2.6 version:

http_port 3128 transparent

dansguardian 2.8 with anti-virus 6.4.3:

filterip =
filterport = 8080
proxyport = 3128

accessdeniedaddress = 'http:localhost/cgi-bin/dansguardian.pl'

firewall script:

#!/bin/sh

PATH=/usr/sbin:/sbin:/bin:/usr/bin

#
# delete all existing rules.
#
iptables -F
iptables -t nat -F
iptables -t mangle -F
iptables -X

# Always accept loopback traffic
iptables -A INPUT -i lo -j ACCEPT


# Allow established connections, and those not coming from the outside
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -m state --state NEW -i ! eth1 -j ACCEPT
iptables -A FORWARD -i eth1 -o eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT

# Allow outgoing connections from the LAN side.
iptables -A FORWARD -i eth0 -o eth1 -j ACCEPT

# Masquerade.
iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE

# Don't forward from the outside to the inside.
iptables -A FORWARD -i eth1 -o eth1 -j REJECT

# Enable routing.
echo 1 > /proc/sys/net/ipv4/ip_forward

# Transparent proxying
iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3128

Thank you for troubling yourselves to answer my query. God bless to us all