DOCBOOK: Image on front cover?

Where do I put information about an image that is to appear on the front 
cover of my book?

I think it can go in bookinfo like so:

   <bookinfo>
     <mediaobject>
       <imageobject>
         <imagedata fileref="../../images/bhs.gif" format="gif">
       </imageobject>
     </mediaobject>
   </bookinfo>

But I does not appear on the book cover.

Michael.

PS My apologies, I don't know if this is a DocBook markup or a stylesheet 
problem that I am having.

--
Dr Michael Baker, 29 Dunmore St, Balfron, GLASGOW G63 0TU
ICQ#16604930, Ph: +44 1360 440803 Mobile: 07890 193698
<> A Saner Future? <http://pobox.com/~mbaker/ideas/>