No login challenge

Hello to the group.

I'm running Apache 2.0.40 on Red Hat 2.4.18-14. I've established a
perl-based web site that runs fine. When I turn on security by adding
Authentication per Apache 2.0 documentation, I cannot get Apache to issue a
login challenge window. I've tried the placing commands in both the
<directory format in httpd.conf and using .htaccess. Help would be
appreciated.

Thanks,

Ted