virtual void Layout()
	{
		Size sz=GetSize();
		int w1,h1,w2,h2;
		
		w1=sz.cx*5/7;
		h1=sz.cy*5/7;
		w2=sz.cx-w1;
		h2=sz.cy-h1;
		lt.SetRect(0,0,w1,h1);
		rt.SetRect(w1,0,w2,h1);
		lb.SetRect(0,h1,w1,h2);
		rb.SetRect(w1,h1,w2,h2);
	}