Works fine for me; IE6, NS7, and NS4 all give identical results to your implementation.
http://www.undefined.net/null/html.html
EDIT:
I have the "function()" part in there, it's near the beginning of the code and is added to each template string. Look again and you'll see it.
The copyright was exised to save space, as you already had a comment in the code explaining the same thing, and status-bar messages often interfere with browsing. If you'd like to put it back in, go right ahead.