I am getting following error while converting the CVS repository to SVN repository using cvs2svn

I am getting this error while while giving this command:

 cvs2svn --trunkonly --svnrepo /path/to/new/svn /path/to/existed/cvs/repo

The error i am getting is

   Error summary:
   ERROR: No RCS files found
   Are you absolutely certain you are pointing cvs2svn
   at a CVS repository?

I found that the my repository is CVSNT. so the above may not be working. Can anybody please give me some idea how to covert those repositories into SVN?

As the error says: The path /path/to/existed/cvs/repo is probably wrong. Try again with the directory which contains CVSROOT.