How to get a View handle?

[lab1]

Hello,

I tried the following code:

CDisplayView* view = dynamic_cast<CDisplayView*>(((CFrameWnd*)AfxGetMainWnd())->GetActiveView());

but it gives me an error for DisplayView.h:

error C2065: 'IDD_DISPLAY_FORM' : undeclared identifier


Any idea why I get this error?

Thanks!