var message="© Copyright Serge Ashmansky, 2002\n\tserge@iftp.ru"; 

function click(e) {
 if (document.all) {
  if (event.button == 2) { alert(message); return false; }
 }
 if (document.layers) {
  if (e.which == 3) { alert(message); return false; }
 }
}
if (document.layers) {
 document.captureEvents(Event.MOUSEDOWN);
}
document.onmousedown=click;