file-question. easy.

hello.

I made this code:
-------------------
#include <iostream>
#include <windows.h>
using namespace std;
int main(){
FILE *Fp;
Fp = fopen("input.dat","r");
if (Fp == NULL) {
  fprintf(stderr, "Can't open input file!\n");
  exit(1);
}
-------------------

I have input.dat (version 1) located at:
"C:\\Program Files\\Microsoft Visual Studio\\MyProjects\\inlezenvanbestand\\input.dat"

and my program is here:
"C:\\Program Files\\Microsoft Visual Studio\\MyProjects\\inlezenvanbestand\\release\\aa.exe"

I have allso a input.dat (version 2) located here:
"C:\\Program Files\\Microsoft Visual Studio\\MyProjects\\inlezenvanbestand\\release\\input.dat"
version 1 of input.dat is different from version 2.

The strange thing is:
when I run my program it opens version 1 of input.dat  .
I want it to open the version in the directory of the exe (version 2).

so, my questions:
(1)-> How should I adapt the code so that it allways opens the file that is placed in the directory of the program itself (and,  I don't want to have the file-pad "hardcoded" in the exe)
(2)-> How comes it opens the version 1 file ?? I don't think this is very logic , since it is placed one directory up !

Any advice is welcome...

Greetz, André.