using libpq++.h

I am new in this and really appreciate some help.

I am able to compile my interface, but get an error when I tried to
execute it:

error while loading shared libraries: libpq++.so.4: cannot open shared
object file: No such file or directory

I can see I do have that file in /pgsql/lib

I compiled it with:
g++ -g main.o database.o -L/.../pgsql/lib -lpq++ -lpq

main.o: main.cpp database.h
g++ -I/.../pgsql/include -g -c main.cpp

data_source.o: database.cpp database.h
g++ -I/.../pgsql/include -g -c data_source.cpp

Thanks a lot for any help.