What would be the cleanest way to build a single page out of multiple html files? I use server side includes on my webserver, but I can't support the traffic load I am hoping to get. I use a common nav bar on my site and don't want to use frames. I don't want to have to update every page when I change something. I was thinking about doing what I did with CSS... and using:

<script src="rollover.js" language="JavaScript"></script>

to import the script with the html I want on it. I guess it is pretty clean but am I just over doing it.... Any easier ways?