SetTimer issue

I have 2 classes

class Cmyclass1 : public CFormView
class Cmyclass2 : public CWnd

Cmyclass1 creates an instance of Cmyclass2

Cmyclass2* pmc2 = new Cmyclass2;

and then calls
pmc2->myfunc

which then sets a timer
m_timerVal = SetTimer(500, 2000, NULL);

but this generates an "assertion failed" in afxwin2.inl line 193

If you look at that line of code, what's it asserting? I'd guess that
its because you've not created the window (for Cmyclass2).

Dave