Ubuntu Networking :: Bridging Firewall - How To Block Incoming Traffic

I have a ubuntu computer set up as bridge between gateway and lan, with the lan connected to eth0 and gateway on eth1.

I'm trying to get it to basically block everything incoming except for the ports i specify, but also allow outgoing traffic. I've found, tried, modified som examples i found on the web, but still it wont block incoming traffic (ie, im still able to reach my webserver)

These are the rules, and i can't figure out why it wont block:

Code:
#!/bin/bash
iptables -F
iptables -X
iptables -I INPUT -i eth1 -j DROP

[Code].....