port forwarding port 80

Hey all. I need some help with port forwarding. I have successfully forwarded port 21 and accessed my FTP, but I can’t seem to get port 80 working to access my web server. I’m using Xerver, which might be the problem. It works on my LAN, but when I connect from an outside IP it won’t find the domain. I’m using a Belkin (first mistake) but I don’t think that’s the problem. Any help would be appreciated. Thanks.