Button and CheckBox are not visible

Hi EveryOne!
i am desigining a button and checkbox on 80's  SDk.
but the controls are not visible.
complete cpde executed correctly.
ths code is given below:

i am writing this in :CHelloWorldBasicAppView
                             -------------------------------------
    CreateWindowL();
    SetRect(aRect);
    SetBlank();

    CEikCheckBox * chkbox = new(ELeave)CEikCheckBox();
    chkbox->SetContainerWindowL(*this);
    chkbox->SetObserver((MCoeControlObserver*)this);
    chkbox->SetExtent(TPoint(100,100),chkbox->MinimumSize());
    chkbox->SetFocus(ETrue);
    chkbox->DrawNow();
       
    CEikCommandButton *BtnSave = new (ELeave)    CEikCommandButton();
    BtnSave->SetContainerWindowL(*this);
    BtnSave->SetTextL(_L(" Save "));
    BtnSave->SetObserver((MCoeControlObserver*)this);   
    BtnSave->SetExtent(TPoint(150,150),BtnSave->MinimumSize());
    BtnSave->DrawNow();
    SetBorder(TGulBorder::EFlatContainer);

    CknEnv::Skin().SetAppViewType(ESkinAppViewWithCbaNoToolband);

    ActivateL();



help me its urgent !!!!!!