Where to add Site Statistics code?

I have a script that keeps track of site statistics and writes the info to a db. To get stats for specific pages there is a small line of javascript that has to be inserted into the code of each page.
However the problem I had is that I only wanted to track the default page and not all of the forums & posts. When I entered the code into default.asp each page on the Forums that each user visited was tracked anyway. Not a major problem except that the db would become bloated with more info than I require.

My guess is that the problem is due to the way the Forums are set up with page 'includes'. If I wanted to only track referrer's and such on the main Forum page only, where would be the best place to insert the code?
Any ideas?