[Nyctos Kasignete]

Код:

procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  if Button = mbRight then
    TrackPopupMenu(PopupMenu1.Handle, TPM_RIGHTALIGN, Mouse.CursorPos.X,
                   Mouse.CursorPos.Y, 0, PopupList.Window, nil);
end;