如何使用js屏蔽鼠标右键

<script type="text/javascript">
            /*
               //for ie6,7,8,9,10 and webkit and opera
                 document.oncontextmenu = function () {
                 window.event.returnValue = false;
                 }
           */
              //for ie6,7,8,9,10 and webkit and opera and firefox
                 document.oncontextmenu=function(e){
                 return false;
                 }
</script>

http://wangye.org/blog/archives/932/