i hope this topic is on the right place...

I want to cofigure my "localhost" to be accesible by some user's.
I have done this before with a usb-adsl modem and IIS. (and a setting by my ISP)
Now i have a different adsl connection (bridged mode) and a router behind my modem. I opened the port 80 and tried to access my (local) server via my ip-address but it doesn't work.
Is there a special setting in apache?

or something else?

please help.