Mw3 simple trainer

Hey guys, i have been learn c++ for about 3 weeks, and decided to make a quick ammo trainer for SP.

#include <iostream>
#include <Windows.h>
#include <string>
using namespace std;

DWORD pid;
DWORD ammo = 0x0F820A0;
int myammo = 900;

int main()
{
HWND hWnd = FindWindowA(0, ("iw5sp"));
GetWindowThreadProcessId(hWnd, &pid);
HANDLE pHandle = OpenProcess(PROCESS_ALL_ACCESS, FALSE, pid);

WriteProcessMemory(pHandle, (LPVOID)ammo, &myammo, sizeof(myammo), 0);

system("pause");

}

That's my code, but when i execute it nothing happens in my game :|

Where did i go wrong? Thanks

- - - Updated - - -

Disregard this, solved it

i had the wrong address and window name