writeproccessmemory help

[Hawkpath]

Hello, I need help with the following code:

#include <windows.h>
#include <tlhelp32.h>
#include <conio.h>
#include <stdlib.h>
#include <iostream>

bool ChangeMemVal(const char * ProcessName, LPVOID MemAddress, int NewVal, int size);

int main()
{
     printf("=== Pinball Trainer Example. Made by Hawkpath ===\n\n");
     if(ChangeMemVal("pinball.exe", (void*) 0x000F4240, 1000000, 4))
          printf("The score has been edited successfully.\n");
     else
          printf("An error occured while attempting edit the score.\n");
     system("PAUSE");
     return 0;
}


/* This function modifys a memory address according to its arguments.
   Arguments :
             ProcessName - the process we want to modify
             MemAddress - the memory address we want to modify
             NewVal - the value we want to change the memory address to
             size - the size of the memory address
   Returns :
           the success of the edit.
   */


bool ChangeMemVal(const char * ProcessName, LPVOID MemAddress, int NewVal, int size)
{
     HANDLE hProcessSnap;
     HANDLE hProcess = NULL;
     PROCESSENTRY32 pe32;
     hProcessSnap = CreateToolhelp32Snapshot( TH32CS_SNAPPROCESS, 0 );
     pe32.dwSize = sizeof( PROCESSENTRY32 );
     Process32First(hProcessSnap, &pe32);
     do
     {
          if(!strcmp(pe32.szExeFile, ProcessName))
          {
               hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, pe32.th32ProcessID);
               break;
          }
     }
     while(Process32Next(hProcessSnap, &pe32));
     CloseHandle( hProcessSnap );
     if(hProcess != NULL)
     {
          WriteProcessMemory(hProcess, MemAddress, &NewVal, size, NULL);     // write the value
          CloseHandle(hProcess);
          return true;
     }
     return 0;
}

The program runs, and the window says: Score edited successfully, but the score stays the same.
Thank you!