How to make a Nametag Changer application

#include <iostream>
#include <windows.h>

using namespace std;

int main()
{
LPCWSTR WindowName = L"Modern Warfare 2";
HWND hwnd = FindWindow(0 , WindowName);
if (hwnd == 0)
{
cout << "Game is not opened!";
std:Exit();
}
else
{
cout << "Game is opened!";
system("Pause");
}
return 0;
}

DWORD process_ID;
GetWindowThreadProcessID(hwnd, &process_ID);
HANDLE hProcess = OpenProcess(PROCESS_ALL_ACCESS, FALSE, process_ID);

int nametag;
DWORD newdatasize = sizeof(nametag);
//here il turn it to a if function to ignore errors...

if(WriteProcessMemory(hProcess , (LPVOID)OFFSETHERE , &nametag , newdatasize , NULL))
{
cout << "Congrats!" << endl;
system("Pause");
}
else
{
cout << "Oops" << endl;
}