if (window.Event) 
document.captureEvents(Event.MOUSEUP); 
function nocontextmenu(){ 
 event.cancelBubble = true 
 event.returnValue = false; 
 return false; 
} 
function norightclick(e){ 
 if (window.Event){ 
  if (e.which == 2 || e.which == 3) 
  return false; 
 } 
 else 
  if (event.button == 2 || event.button == 3){ 
   event.cancelBubble = true 
   event.returnValue = false; 
   return false; 
  } 
} 
document.oncontextmenu = nocontextmenu; // for IE5+ 
document.onmousedown = norightclick; // for all others