unable to reference error while running epanet_toolkit.

[Rahulghuge94]

im running sample programs from epanet in gcc. i have kept required headers in same directory but program unable to find the function inside header file.
#include <stdio.h>
#include "epanet2_2.h"

int main()
{
EN_Project ph;
int error;

error = EN_createproject(&ph);
error = EN_open(ph, "Example.inp", "net1.rpt", "");

}