做多线程实验是出现错误~望高手指教

#include <stdio.h>
#include <Windows.h>
DWORD WINAPI myfun1(LPVOID lpParameter);
DWORD WINAPI myfun2(LPVOID lpParameter);
static int al=0;
CRITICAL_SECTION Section;
int _tmain(int argc, _TCHAR* argv[])
{
HANDLE h1,h2;
h1=::CreateThread(NULL,0,myfun1,NULL,0,NULL);
printf("线程1开始运行\r\n");
h2=::CreateThread(NULL,0,myfun2,NULL,0,NULL);
printf("线程2开始运行\r\n");
::CloseHandle(h1);
::CloseHandle(h2);
InitializeCriticalSection(&Section);
::Sleep(10000);
if(getchar()=='q')
{
DeleteCriticalSection(&Section);
}
else
{
return 0;
}
}

DWORD WINAPI myfun1(LPVOID lpParameter)
{
while(true)
{
EnterCriticalSection(&Section);
al++;
if (al<1000)
{
::Sleep(1000);
printf("线程1正在计数%d\r\n",al);
LeaveCriticalSection(&Section);
} 
else
{
LeaveCriticalSection(&Section);
break;
}
}
return 0;
}

DWORD WINAPI myfun2(LPVOID lpParameter)
{
while(true)
{
EnterCriticalSection(&Section);
al++;
if (al<1000)
{
::Sleep(1000);
printf("线程2正在计数%d\r\n",al);
LeaveCriticalSection(&Section);
} 
else
{
LeaveCriticalSection(&Section);
break;
}
}
return 0;
}

运行后弹出"0x7c939af2"指令引用的"0x00000010"内存。该内存不能为"written"。

代码都是按书打的不知道错在哪。



[解决办法]
InitializeCriticalSection(&Section);
请放所有线程创建之前。