Unresolved extern symbols - Mailing list pgsql-interfaces

Hello,

I'm trying to link on Windows (Visual C++) a libpq project that runs
fine in MacOS X, I get this error eleven times :

Unresolved extern symbols  _PQStatus...
Unresolved extern symbols  _PQErrorMessage...

...etc...

What is supposed to generate this link errors ?

Thanks

Regards.

Stéphane