Understanding the router's webpage source code

Hello,

I'm just starting to digg around in the source code of Merlin.
I'm trying to get my head around the /www folder and how it creates the webinterface of the router that we all love so much.

I started by looking at the index.asp.
First hurdle that I found was that I can not anywhere find the definition of nvram_get() or login_state_hook() or any other function that is enclosed by <% and %>

I somehow have the feeling that these are "server side" generated functions but they should somewhere showup in the source code of the router. I searched through the git repository but no avail ... I can not find any definition of these functions.

Who can help ?

Marc