Binary large object processing problems

Hi

I am novice in pogres C API user and I want to store Binary Large Object into database from C language program.

I am using following source :

Oid nloid = lo_import(conn, FileFUllName.c_str());

if (nloid == 0) {
std::cerr << "Error importing large object: " << PQerrorMessage(conn) << std::endl;
return -1;
}
else {
std::cout << "Large object imported successfully with fd " << nloid << std::endl;
}

And I seadely get 0 from lo_import.

I tried to create it previously an send oid to lo_impor_with_oid, but with error

Can anybody help me find where is my mistake an what is working solution ?

Regards,

Raivo