CreateMutex实现只能打开一个客户端

#include "stdafx.h"

#include <Windows.h>

#include <iostream>

using namespace std;

int _tmain (int argc, LPTSTR argv[])

{

    HANDLE h=CreateMutex(NULL,TRUE,"AAAAAAA");

    if(GetLastError()==ERROR_ALREADY_EXISTS){

        CloseHandle(h);

        return ;

    }

    system("pause");

    CloseHandle(h);

    return ;

}