"error C2065: 'ON_WM_THEMECHANGED' : undeclared identifier"

I'm using VC6.How to solve the error?

error C2065: "error C2065: 'ON_WM_THEMECHANGED' : undeclared identifier"

Class Definition Code:

    #include "stdafx.h"
    #include "ConfigListCtrl.h"
    #include "CellCtrls\ListCtrlCellWnd.h"
    #include "CellCtrls\CellButton.h"
    #include "Windows.h"
    #include "Winuser.h"
    // CConfigListCtrl

    IMPLEMENT_DYNAMIC(CConfigListCtrl, CListCtrl)

    CConfigListCtrl::CConfigListCtrl() : m_bInit(FALSE), m_bCaretExists(FALSE), m_bTabbedIn(FALSE), m_bKeyUp(FALSE), m_bIsEnabled(TRUE)
    {
    }

    CConfigListCtrl::~CConfigListCtrl()
    {
        ForEachCellCtrl(&CConfigListCtrl::DeleteCellCtrl);
    }

    BEGIN_MESSAGE_MAP(CConfigListCtrl, CListCtrl)
...
        ON_WM_THEMECHANGED()
...
    END_MESSAGE_MAP()
    ...
    }

It seems that I have missed some header file or lib file, but what are they, how to solve it anyway?

Themes were first introduced with Windows XP, several years after VC6. You will need an updated Windows SDK with the appropriate win... .h files.