JavaScript 网页的右键菜单怎么屏蔽?

就是如图的东西,怎么才能屏蔽掉?我写了稍微一点了,希望能帮回答的人省点力气..

$(document).on("contextmenu",   )

---

document.oncontextmenu = function(){
    return false;
} 

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恕我直言，屏蔽了也没特大用
现在很多第三方浏览器都有禁止屏蔽……

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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