Visual c++ 6.0: error C2065: 'PWR_CString' : undeclared identifier

This error for th开发者_开发技巧e following: C:\software\CATS\includes\Commun\xml_transfer.cpp(1527) : error C2065: 'PWR_CString' : undeclared identifier

CString s1;                    // Empty string

I did include:"stdafx.h" , "resource.h"