Why 'Trim' : is not a member of 'CString'

Hello all i have simple app that i try to compile with VC express and using the :
microsoft platform sdk for windows server 2003 that contains mfc and atl
now i have this simple code :


CString strValue("test");
CString s = strValue.Trim();
LPCTSTR lpStr = (LPCTSTR)strValue.Trim()


hat give me compilation error : c:\dev\test.cpp(463) : error C2039: 'Trim' : is not a member of 'CString' c:\program files\microsoft platform sdk for windows server 2003 r2\include\mfc\afx.h(369) : see declaration of 'CString'

do i have problem with the platform sdk and vc express ?