javascript仿QQ网站新闻图片轮换效果

<script> //鼠标移过来的动作。显示当前图片，清除轮询。 function adchangea(adid) { dochange(adid); clearTimeout(adisround); } //自动轮询 function adchangea2(adid) { dochange(adid); var adbigimg = document.getElementById("adpica").getElementsByTagName("div"); if ((adnext = adid 1) > adbigimg.length) adnext = 1; adisround = setTimeout('adchangea2(' adnext ')', 3000); } //显示当前图片 function dochange(adid) { id = adid; var adbigimg = document.getElementById("adpica").getElementsByTagName("div"); var adsmallimg = document.getElementById("adtipa").getElementsByTagName("li"); for (var adi = 0; adi < adbigimg.length; adi ) { adbigimg[adi].className = "hidden"; adsmallimg[adi].className = ""; } adbigimg[adid - 1].className = "show"; adsmallimg[adid - 1].className = "current"; } var adisround = setTimeout("adchangea2(2)", 3000); var id;//当前激活id //鼠标移开ul块时，恢复轮询 function change() { adchangea2(id); } </script>