Embed another page in a HTML file using the embed tag?

I currently have a singe HTML file (sitemap.html) that I am embeding (Using the embed tag) on all the pages of my website so that I only need to update that one file to update the navigation links on all of my pages. The problem is that this only works in certain browsers (Chrome/IE8/9) And not others (Most notably Firefox).

Is there another way to do this that is more browser compatible?

P.S. H开发者_运维百科ere is a link to my actual site so you can see (the source) for yourself: http://fenrirmedia.dyndns.org/

A great way, I've been using a lot before I started using PHP was this:

<!--#include virtual="/sitemap.html"--> for absolute paths
and
<!--#include file="sitemap.html"--> for relative paths.

It should be working in all browsers