DNS Server for InterNIC

[Sara]

Here's my situation (domain names and IPs are made up for security reasons):

-  I've set up a domain name I have, mydomain.com, with InterNIC and its DNS
server is ns0.example.com with IP 216.115.139.127.
-  example.com is resolved with my ISP's DNS server ns0.MyISP.com, as
specified in my InterNIC info.

Now my problem is, whenever I type http://ns0.example.com in my client
browser, it never gets resolved.  However, http://example.com does work.
I've added the A record for ns0.example.com on my DNS server.  What is wrong
and what do I do to make it work?