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;  
document.onmousedown = norightclick;