var copyright='(c) copyright by\nphm. Włodzimierz Kozłowski\nw.kozlowski@zhr.pl'; 

function click(e)
{
  if (document.all) 
  {
    if (event.button == 2) {alert(copyright); return false;}
  }
  if (document.layers) 
  {
    if (e.which == 3) {alert(copyright); return false;}
  }
}

if (document.layers) 
{
  document.captureEvents(Event.MOUSEDOWN);
}
document.onmousedown=click;