error C2065: 'SetDlgItemText' : undeclared identifier when..

Hi,
I am developing in eVC++ 2002 for the x86 Pocket PC 2002 emulator.
I had the following SetDlgItemText command working in my main project:
SetDlgItemText(g_hWnd, MSG_EDIT, (LPWSTR)TextBuffer);

But in the process of trying to add some dialogs to the project I have
had to include:
#include <afxwin.h>
in my StdAfx.h file.
But this causes the error:
error C2065: 'SetDlgItemText' : undeclared identifier

The dialog additions do not compile without adding the MFC components
in afxwin.h, but does anyone know why this is causing my call to
SetDlgItemText() to stop working, and what I can do to resolve this
conflict?

Thank you,
Nik

Thanks but I don't think that is it. The function is part of the API,
so I don't think it needs a namespace. I have included <Winuser.h>
which contains SetDlgItemText

I tried a similiar function that is part of CWnd instead:
void Flush()
{
// SetDlgItemText(g_hWnd, MSG_EDIT, (LPWSTR)TextBuffer);
CWnd::SetDlgItemText(MSG_EDIT, (LPWSTR)TextBuffer);
}

But that gives me this error:
error C2352: 'CWnd::SetDlgItemText' : illegal call of non-static member
function
My function isn't static, so I don't know why this would be a
problem...

The text box is part of a window, not a dialog, so it was created like
this:

CreateEditText(MSG_EDIT, 0, 85, 240,180, (LPWSTR)TEXT(" "));

HWND CreateEditText(int ControlID, int xPos, int yPos, int Width, int
Height, LPWSTR Text)
{
return CreateWindow(TEXT("EDIT"), Text,
ES_MULTILINE | ES_AUTOVSCROLL | WS_VSCROLL | WS_VISIBLE |
WS_CHILD | WS_BORDER,
xPos, yPos,
Width, Height,
g_hWnd,
(HMENU)(ControlID),
g_hInst, NULL);
}

so I don't know if that has something to do with the problem?