// Step 4: the Window Procedure
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
case WM_CLOSE:
DestroyWindow(hwnd);
break;

case WM_DESTROY:
PostQuitMessage(0);
break;

case WM_COMMAND:

switch (LOWORD(wParam))

{
case IDABOUT:

MessageBox(NULL, "Trying this window thing out", "Whoa",
MB_ICONEXCLAMATION | MB_OK);

break;
case D_ABOUT:

int ret = DialogBox(GetModuleHandle(NULL),
MAKEINTRESOURCE(IDD_ABOUT), hwnd, AboutDlgProc);

break;


}




break;



default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;
}


This is what I get.

Error Codes:



--------------------Configuration: Project - Win32 Debug--------------------
Compiling resources...
Compiling...
main.cpp
C:\Documents and Settings\incognito\My Documents\Win32 Project\Project\main.cpp(32) : error C2065: 'D_ABOUT' : undeclared identifier
C:\Documents and Settings\incognito\My Documents\Win32 Project\Project\main.cpp(32) : error C2051: case expression not constant
C:\Documents and Settings\incognito\My Documents\Win32 Project\Project\main.cpp(35) : error C2065: 'IDD_ABOUT' : undeclared identifier
C:\Documents and Settings\incognito\My Documents\Win32 Project\Project\main.cpp(35) : error C2065: 'AboutDlgProc' : undeclared identifier
C:\Documents and Settings\incognito\My Documents\Win32 Project\Project\main.cpp(56) : error C2373: 'AboutDlgProc' : redefinition; different type modifiers
Error executing cl.exe.

Project.exe - 5 error(s), 0 warning(s)



Thanks in advance.