传Facebook正在研发神秘的视频聊天设备和智能音箱

window.onload = function (){ var oLi = document.getElementById("tab").getElementsByTagName("li"); var oUl = document.getElementById("ms-main").getElementsByTagName("div"); for(var i = 0; i < oLi.length; i++) { oLi[i].index = i; oLi[i].onmouseover = function () { for(var n = 0; n < oLi.length; n++) oLi[n].className=""; this.className = "cur"; for(var n = 0; n < oUl.length; n++) oUl[n].style.display = "none"; oUl[this.index].style.display = "block" } }}