js点击列表文字对应该行显示背景颜色的实现代码

<style type="text/css">li{cursor:pointer;}.cur{background:red;}</style><script type="text/javascript">window.onload = function (){ var aLi = document.getElementsByTagName("li"); var i = 0;  for (i = 0; i < aLi.length; i++) {  aLi[i].onclick = function () {  for (i = 0; i < aLi.length; i++) aLi[i].className = "";  this.className = "cur"; }; }};</script><div class="clMenu">  <ul>    <li>1</li>    <li>2</li>    <li>4</li>    <li>5</li>  </ul></div>