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;