Morning all

I'm trying to add a small "bookmark me button" to my website..
It works fine for Internet Explorer.
But when I try to use it viewing the site using firefox, "computer says no"! (in fact, it doesn't say anything ... just doesn't do anything).

Does anybody know a bit of code that would work for both browsers? I'm not having much luck with codes found via google searches

At the moment, i'm using ....
<CENTER><img src="http://www.mywebsite.com/images/bookmark.png" onclick="window.external.AddFavorite(location.href, document.title);"></CENTER>
Thanks