procedure TForm1.ScrollBar1Scroll(Sender: TObject; ScrollCode: TScrollCode;
  var ScrollPos: Integer);
  var p : integer;
begin
p := Scrollbar1.Position;
  RichEdit1.SelStart := RichEdit1.Perform(EM_LINEINDEX, p, 0);
  memo4.SelStart := memo4.Perform(EM_LINEINDEX, p, 0);
  memo4.SelLength := 0;
  RichEdit1.SelLength := 0;
  form1.ScrollBar1.Max := form1.Memo4.Lines.Capacity-1;
end;