Auto Refresh frame

Okay, I posted this original question:
I have a remote webcam at a summer camp that I am webmaster for. I use iWeb for the site. Currently we have the webcam feeding to another url. How can I get that to show on a page on our site?

I got a great answer that works:
Display the other url in a HTML Snippet with the <iframe> element.
<iframe src="http://url.to.file.html" frameborder="0" width="500" height="500" scrolling="no" allowTransparency="true"></iframe>

Now I need that frame to refresh on it's own. How would I set that up? How would that html tie-in with the other?
Thanks