ORA-12154: TNS:could not resolve service name

[green_tea]

Hello,
I'm developing a web application that will return data from our
Oracle9i database.
When I run it within Visual Studio 2005 (use
http://localhost:2145/infuse/, it retrieves all of the data and works
just fine.
But, when I build,/publis, execute, and invoke it through a defined
website (intranet), e.g http://ay3apwev.ap.com/infuse/ , I get the
error: "TNS:could not resolve service name"

These 2 URLs are point to the same directory, they use exactly the same
set of files on the same machine. But the localhost url works, the
"real" one didn't.

Could anyone help me with this? Thanks a lot.

Green.