html question: setting relative path to cgi-bin script

[Peter S Galbraith <GalbraithP@dfo-mpo.gc.ca>]

Background:

 My mh-book package has an index search engine as a cgi script.
 The current version assumes all invocations are done on the
 localhost, and I want to make the package fully functional if
 called remotely.
 
 I changed the cgi script itself to return relative paths like
 "/doc/mh-book/html/SOMEFILE.html" so this will work whether the
 script was called locally with
 http://localhost/cgi-bin/mh-book-index or remotely using
 http://SERVERNAME/cgi-bin/mh-book-index.

Problem:

 The problem is invoking the cgi script in the first place
 without knowledge of the server name.  If I place a link to
 /cgi-bin/mh-book-index in an HTML page, the link will work if
 that HTML page was initially called with http://, but if I
 instead called that page using file:/usr/... then the relative link
 becomes file:/cgi-bin/mh-book-index and is broken.

 AFAIK, there's no HTML relative tag that specifies a path but
 not a server (e.g. use the same server as for this page?),
 something like http:///cgi-bin/mh-book-index.

 I'm trying to avoid having a postinst script that prompts for a
 server name, and inserts it in a static html page in
 /usr/doc/mh-book/html/ but that seems unavoidable (I guess that
 page would have to be moved to /var/lib/mh-book as well?).  I
 could also depend on dwww and use its DWWW_SERVERNAME entry in
 /etc/dwww/dwww.conf instead of prompting, or create my own
 config script based on /usr/sbin/dwwwconfig to guess the server
 name.

 What a pain... Any suggestions?

Thanks
-- 
Peter Galbraith