// From: Karsten Heitmann 

procedure TForm1.FormShow (Sender: TObject);
var
  atom : integer;
  CRLF : string;
begin 
  if GlobalFindAtom ('THISISSOMEOBSCUREETEXT') = 0 then 
    atom := GlobalAddAtom ('THISISSOMEOBSCUREETEXT') 
  else 
  begin 
    CRLF := #10#13; 
    ShowMessage ('This version may only be run once every Windows Session.' 
      + CRLF + 
      'To run this application again, you need to restart Windows,'
      + CRLF + 'or purchase a license.!!'); 
    Close 
  end 
end;