javascript实现网页屏蔽鼠标右键

<script language="JavaScript">

<!--
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
//-->
</script>