Why wouldn't you just look at your server logs to figure out who came from where? Barring that, you probably don't want to put a reference to a script into an <img> tag. You probably want to capture the environment variable in your main script for that page. That's the only reliable time the browser is going to set referrer to a URL from somewhere else. Of course, I see that you want to track this for a static HTML file, which brings you back to server logs. I've never heard a compelling reason to use SSI over simply writing a Perl script to replace index.html with index.pl.