屏蔽右键（javascript）兼容ie，firefox

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   http://www.my400800.cn