Sharepoint:Add a URL mapping to the web application

I created a sharepoint application with http://tlc-tndc.dyndns.org/. I could access the sharepoint application using the URL. However, internal user wants to use http://tndc-main/, the Netbios name.

Configure the Web Application in IIS with multiple host header mapping as shown below:

Access the web application with both http://tlc-tndc.dyndns.org/ and http://tndc-main/ without problem. However, with http://tndc-main/, you cannot use the search feature. It gives you the error message: Add a URL mapping to the web application. How?

Sharepoint 3.0 Central Administration

--Operations

--Alternate Access Mapping

Add an internal URLs

http://tndc-main/

done!