js+css 控制表格隔行着色，单行高亮

代码片段如下：

<style type="text/css" media="screen">
table {border-collapse:collapse;border:solid #999;border-width:1px 0 0 1px;}
table td {border:solid #999;border-width:0 1px 1px 0;}
tr.t1 td {background-color:#fff;}/* 第一行的背景色 */
tr.t2 td {background-color:#eee;}/* 第二行的背景色 */
tr.t3 td {background-color:#ccc;}/* 鼠标经过时的背景色 */
tr.t4 td {background-color:#E2EBED;}
</style>

 

<table border="1" width="100%" id="tab">
    <tr><td>11</td><td>11</td><td>11</td></tr>
    <tr><td>11</td><td>11</td><td>11</td></tr>
    <tr><td>11</td><td>11</td><td>11</td></tr>
    <tr><td>11</td><td>11</td><td>11</td></tr>
    <tr><td>11</td><td>11</td><td>11</td></tr>
    <tr><td>11</td><td>11</td><td>11</td></tr>
    <tr><td>11</td><td>11</td><td>11</td></tr>
    <tr><td>11</td><td>11</td><td>11</td></tr>
    <tr><td>11</td><td>11</td><td>11</td></tr>
    <tr><td>11</td><td>11</td><td>11</td></tr>
    <tr><td>11</td><td>11</td><td>11</td></tr>
    <tr><td>11</td><td>11</td><td>11</td></tr>
    <tr><td>11</td><td>11</td><td>11</td></tr>
    <tr><td>11</td><td>11</td><td>11</td></tr>
</table>
<script type="text/javascript">
var Ptr=document.getElementById("tab").getElementsByTagName("tr");
function $() {
    for (i=2;i<Ptr.length+1;i++) {
        Ptr[i-1].className = (i%2>0)?"t1":"t2";
    }
}
window.onload=$;
for(var i=1;i<Ptr.length;i++) {
    Ptr[i].onmouseover=function(){
    thisthis.tmpClass=this.className;
    this.className = "t3";
    };
    Ptr[i].onmouseout=function(){
    thisthis.className=this.tmpClass;
    };
}
</script>