External IP access to IIS

I have IIS server up and running on my Windows XP machine. I can access the server from local network, and now I want to be able to access it from the internet, using my external IP address. Here is what I have done so far, and it is still not working. Firewall is shut down so it is not the problem.

1) set up the IIS to use port 40 (I can access through that port locally) 2) set up NAT in router to forward port interval 30-90 (including 40) 3) set up my local machine (which is running IIS) IP address in router NAT (which is 192.168.1.4)

When i try to access it like: :40 i get service timeout, can not connect.

Any suggestions?