window.onload = function() { var oBox = document.getElementById("box"); var aUl = document.getElementsByTagName("ul"); var aImg = aUl[0].getElementsByTagName("li"); var aNum = aUl[1].getElementsByTagName("li"); var timer = play = null; var i = index = 0; var bOrder = true; //切换按钮 for(i = 0; i