procedure TForm1.Button1Click(Sender: TObject);
 var
 pusat: array of TPoint;
 i: Integer;
 begin
 SetLength(pusat, 4);
 for i := Low(pusat) to High(pusat) do
 begin
 pusat[i].x := Random(Width);
 pusat[i].y := Random(Height);
 end;
 Canvas.PolyBezier(pusat);
 end;