Placing controls, wxWindows

[MK]

I have problems while placing wxNotebook in a wxPanel.
For the time being I'm using

    self.SetDimensions(0, 0, 1000, 600)

... in my wxNotebook-derived class, but obviously that's
not what I want. If I omit the line above, then my notebook
shrinks to about 100x20 pixels. (I can barely see the tabs!)
Does anybody know how can I have my wxNotebook
adjust its size automatically, relatively to its parent wxPanel?
Thx,

The hierarchy is:

wxFrame
    wxPanel
        wxNotebook