这是一个线程的例子，能够编译和联接，但不能运行．请高手指教一下．
代码如下：
class CUIThread:public CWinThread
{
DECLARE_DYNCREATE(CUIThread)
public:
virtual BOOL InitInstance();
};

class CMainWindow:public CFrameWnd
{
public:
CMainWindow();
protected:
afx_msg void OnLButtonDown(UINT,CPoint);
DECLARE_MESSAGE_MAP()
};

IMPLEMENT_DYNCREATE(CUIThread,CWinThread)
BOOL CUIThread::InitInstance()
{
m_pMainWnd=new CMainWindow;
m_pMainWnd->ShowWindow(SW_SHOW);
m_pMainWnd->UpdateWindow();
return true;
}

BEGIN_MESSAGE_MAP(CMainWindow,CFrameWnd)
ON_WM_LBUTTONDOWN()
END_MESSAGE_MAP()

CMainWindow::CMainWindow()
{
Create(NULL,_T("UI Threadwindow"));
}

void CMainWindow::OnLButtonDown(UINT nFlags,CPoint point)
{
PostMessage(WM_CLOSE,0,0);
}