[Dspace-general] change dspace.url

[Gay]

hi
I  have a problem to  use an URL without port number

in my dspace.config
dspace.url = http://archive.site.fr:8081/dspace
dspace.hostname = mon.site.fr

  in  server.xml       tomcat

  <!-- Define a non-SSL HTTP/1.1 Connector on port 8080 -->
     <Connector port="8081" maxHttpHeaderSize="8192"
                maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
                enableLookups="true"  acceptCount="100"
                connectionTimeout="20000" disableUploadTimeout="true" 
URIEncoding="UTF-8" />
	
with this code I can access  to my site with 
http://archive.site.fr:8081/dspace
but now I want use an URL without port number	
   example   http://archive.site.fr

what can I modify  to do that
so my user under linux is archive and my directory is like....

/home/archive/dspace
/home/archive/tomcat
/home/archive/pgsql
....................

thanks
mireille