if (window.Event) document.captureEvents(Event.MOUSEUP); 

function nocontextmenu()  
{
  event.cancelBubble = true
  event.returnValue = false;
  return false;
}

document.oncontextmenu = nocontextmenu;  
document.onmousedown = norightclick;  

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;
   }
}