HRGN Reg1, Reg2;
   HRGN Region;
   POINT p[5];

   Reg1 = CreateRectRgn(0, 0, Width, Height);
   Reg2 = CreateRectRgn(150, 100, Width-150, Height-100);
   CombineRgn(Reg1, Reg1, Reg2, RGN_XOR);
   SetWindowRgn(Handle, Reg1, true);

   RECT r;
   HRGN Region;

   r = GetClientRect();
   Region = CreateEllipticRgn(r.left+25, r.top+25, r.right-25, r.bottom-25);
   SetWindowRgn(Handle, Region, true);

   HRGN Reg1, Reg2;
   HRGN Region;
   POINT p[5];

   p[0] = Point(100, 0);
   p[1] = Point(Width-100, 0);
   p[2] = Point(Width, Height/2);
   p[3] = Point(Width/2, Height);
   p[4] = Point(0, Height/2);
   Region = CreatePolygonRgn(p, 5, ALTERNATE);
   SetWindowRgn(Handle, Region, true);