Header/Nav Fireworks

Hi,

I am fairly new to website designing. I have found using adobe fireworks to create headers for my sites with nav links to be fairly useful.

I then export the file to HTML and Images so that i can place it all at the top of my webpage.

I wondered, however, if there is any way of keeping the header/navbar as a single file (or to that effect) so that if I were to alter it in any way all of my pages would be sourcing the same file and would update accordingly. Otherwise I would have to re-source all of the different slices individually and for every page on my website.

Any ideas would be great. Cheers.