Trying to use libpg intrface to postgresql in a windows application.

I use Visual C++ to develop a windows application that communicate using the libq library with a unix Postgresql server
.
I included the libpq-fe.h header file in my source and the libpq.a in the linker files. I try to implement the example
filesi found
 
in the documentation but they all result to an exception from the debuger at the command trying to connect to the dbase
server.ex
 
conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);

Could anyone give me one or two tips to get started with?

thx in advance.