error while loading shared libraries: libpq.so.3

i have written a program sample.c
it is as folllows:
#include<stdlib.h>
#include<libpq-fe.h>
int main()
{
PGconn *myconnection = PQconnectdb("");
printf("Hi");
return 0;
}

I then compile this program using makefile
make sample
cc -I/usr/local/pgsql/include sample.c -L/usr/local/pgsql/lib -lpq -o sample
I then run it....and it gives and error
[indra:/homes/surabi] ./sample
./sample: error while loading shared libraries: libpq.so.3: cannot open shared object file: No such file or directory
Please tell what the problem is..and how should I rectify it?