如何使用MFC工具提示的示例代码修复错误？

#include <afxwin.h>
#include <afxtooltipctrl.h>

class CMyApp : public CWinApp
{
public:
    virtual BOOL InitInstance()
    {
        CWinApp::InitInstance();

        CFrameWnd* pFrame = new CFrameWnd;
        pFrame->Create(NULL, "My Tooltip Example");

        CToolTipCtrl* pToolTip = new CToolTipCtrl;
        pToolTip->Create(pFrame);

        CButton* pButton = new CButton;
        pButton->Create("Click me!", WS_VISIBLE | WS_CHILD | BS_PUSHBUTTON,
            CRect(10, 10, 100, 50), pFrame, 1);

        pToolTip->AddTool(pButton, "Click this button to show a message box.");

        pFrame->ShowWindow(m_nCmdShow);
        pFrame->UpdateWindow();

        return TRUE;
    }
};

CMyApp theApp;