Transparent Proxy and IPChains

["Jason L. Esman" <jesman () edpm com>]

Hello,
 Long time reader first time writer, I have a Linux system using IPChains
and Squid for the proxy/cache. I want to make my people use the proxy to
browse the internet. The Linux box is our gateway to the internet and does
masq no one can get out without going through this box. This is what i've
tried to do:

Squid Conf:
http_port 3128
httpd_accel_host virtual
httpd_accel_port 80
httpd_accel_with_proxy on
httpd_accel_uses_host_header on

IpChains:
/sbin/ipchains -A input -j ACCEPT -i lo -p tcp -d 127.0.0.1/32 80
/sbin/ipchains -A input -j ACCEPT -i eth1 -p tcp -s 192.168.1.0 -d
192.168.1.5/32 80
/sbin/ipchains -A input -j REDIRECT 3128 -i eth1 -p tcp -s 192.168.1.5 -d
192.168.1.255/0 80$

When a user does not setup a proxy server in MSIE or Netscape it don't work.
Any idea, what I want to do is redirect all trafic to the internet to use
port 3128 via the proxy. Any ideas suggestions hints etc...
Thanks,
 Jason L. Esman