<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title></title>
    <script src="Scripts/jquery-1.4.1.js" type="text/javascript"></script>
    <script type="text/javascript">
        /*第一行显示大字体,
        最后一行显示绿色
        前三行显示大字体
        奇数行背景色为红色*/
        $(function () {
            $("table tr:first").css("font-size", "40");
            $("table tr:last").css("color", "green");
            $("table tr:gt(0):lt(3)").css("font-size", "30");
            $("table tr:gt(0):even").css("background", "red");
        });
    </script>
</head>
<body>
<table>
<tr><td>姓名</td><td>成绩</td></tr>
<tr><td>jim</td><td>100</td></tr>
<tr><td>tom</td><td>99</td></tr>
<tr><td>john</td><td>98</td></tr>
<tr><td>green</td><td>97</td></tr>
<tr><td>bob</td><td>96</td></tr>
<tr><td>平均分</td><td>98</td></tr>
</table>
</body>
</html>