This exists in my httpd.conf file: 
<Location /svn>
   DAV 
svn
   SVNParentPath /Users/iirp/Sites/svn
   Allow from all
   #AuthType Basic
   #AuthName "Subversion repository"
   #AuthUserFile /Users/iirp/Sites/svn-auth-file
   #Require valid-user
</Location>
This is working file
When I change this to: 
<Location /svn>
   DAV 
svn
   SVNParentPath /Users/iirp/Sites/svn
   #Allow from all
   AuthType Basic
   AuthName "Subversion repository"
   AuthUserFile /Users/iirp/Sites/svn-auth-file
   Require valid-user
</Location>
and when I access my repository through URL, it gives me the authentication screen but after that screen my 
svn repository is not showing up correctly. 
to see message that it gives to me is: 
  Internal Server Error
  
  The server encountered an internal
  error or misconfiguration and was
  unable to complete your request.
  
  Please contact the server
  administrator, 
[email protected] and
  inform them of the time the error
  occurred, and anything you might have
  done that may have caused the error.
  
  More information about this error may
  be available in the server error log.