为什么会报错哦？关于C++锁的使用?报错

// asdasdsadasd.cpp : 定义控制台应用程序的入口点。
//


#include "stdafx.h"
#include <vector>
#include <Windows.h>
#include <iostream>


using namespace std;


vector<int>strNum;


HANDLE m_mutex;


DWORD WINAPI MyThreadProc1(LPVOID lpParameter)
{ int i=0;
while(1)
{
WaitForSingleObject(m_mutex,INFINITE);
strNum.push_back(i);
i++;
ReleaseMutex(m_mutex);
Sleep(100);
}
}


DWORD WINAPI MyThreadProc2(LPVOID lpParameter)
{
vector<int>::iterator iter;

while (1)
{
WaitForSingleObject(m_mutex,INFINITE);
if (strNum.size()>0)
{
for (iter=strNum.begin();iter!=strNum.end();iter++)
{
cout<<(iter)<<endl;
}
}
ReleaseMutex(m_mutex);
Sleep(100);
}
}


int _tmain(int argc, _TCHAR argv[])
{


CreateThread(NULL,0,MyThreadProc1,NULL,0,NULL);
CreateThread(NULL,0,MyThreadProc2,NULL,0,NULL);


while(1)
{
WaitForSingleObject(m_mutex,INFINITE);
strNum.clear();
ReleaseMutex(m_mutex);
Sleep(100);
}
return 0;
}