You need to understand how includes work. There are relative and absolute includes.
Absolute: <!--#Include Virtual="dir/file.asp"-->
Relativ : <!--#Include File="file.asp"-->
The difference is that absolute includes
always go from the root of your website so if you want to include a file located in e.g.
http://www.mysite.com/home/includes/file.asp you would
always write an absolute statement like that:
<!--#Include Virtual="home/includes/file.asp"--> no matter where you are calling it from.
If you decide to use relative includes it will include it from where you are calling it. so if the calling page is in let's say ../home/app/default.asp and you would like to include the very same file as before you would have to write <!--#Include File="../includes/file.asp"--> Now if you have this file calling another include so if file.asp is calling an include by itself you need to go relative from the include file and not from the first requesting page. For this reason and confusion it is always recommended to use absolute includes because it does not matter where you make the call from. In an application like this forum though it would be almost impossilbe as you never know where people put the forum. so relativ is used.