procedure ScrollBoxMouseWheelHandler(var Msg: TMessage); message WM_MOUSEWHEEL

procedure TForm2.ScrollBoxMouseWheelHandler(var Msg: TMessage);
var
  WheelDelta: Integer;
begin
  inherited;

  if not PtInRect(ScrollBox.ClientRect, ScrollBox.ScreenToClient(Mouse.CursorPos)) then
    Exit;

  with ScrollBox do
  begin
    if Msg.WParam < 0 then
      WheelDelta := -1 * VertScrollBar.Increment
    else WheelDelta := VertScrollBar.Increment;

    if ((VertScrollBar.Position = 0) and (WheelDelta > 0)) or
       ((VertScrollBar.Position = VertScrollBar.Range - ClientHeight) and (WheelDelta < 0)) then
       Exit;

    VertScrollBar.Position := VertScrollBar.Position - WheelDelta;
  end;
end;

procedure TFormDocsKit.ScrollBoxMouseWheelHandler(var Msg: TMessage);
var
  ScrollControl: TWinControl;
begin
  inherited;

  ScrollControl := FindVCLWindow(Mouse.CursorPos);
  if Assigned(ScrollControl) then
  begin
    Caption := TWinControl(ScrollControl).Name;

  end;
end;