jQuery表格隔行变色，鼠标经过变色

th{ height: 30px; line-height: 20px; background: #0093D9; color: #fff;}
        td{ padding: 6px 10px; border-bottom: 1px solid #95bce2; text-align: center; vertical-align: top;}
        tr.alt td{ background: #ecf6fc;}
        tr.over td{ background: #bcd4ec;}

<table class="table" width="50%" border="0" cellpadding="0" cellspacing="0">
        <thead>
            <tr>
                <th>姓名</th>
                <th>年龄</th>
                <th>QQ</th>
                <th>Email</th>
            </tr>
        </thead>
        <tbody>
            <tr>
                <td>张三</td>
                <td>25</td>
                <td>123456789</td>
                <td>zhangsan@qq.com</td>
            </tr>
            <tr>
                <td>张三</td>
                <td>25</td>
                <td>123456789</td>
                <td>zhangsan@qq.com</td>
            </tr>
            <tr>
                <td>张三</td>
                <td>25</td>
                <td>123456789</td>
                <td>zhangsan@qq.com</td>
            </tr>
            <tr>
                <td>张三</td>
                <td>25</td>
                <td>123456789</td>
                <td>zhangsan@qq.com</td>
            </tr>
            <tr>
                <td>张三</td>
                <td>25</td>
                <td>123456789</td>
                <td>zhangsan@qq.com</td>
            </tr>
        </tbody>
    </table>

$(function(){
        $(‘.table tr‘).hover(function(){
            $(this).addClass(‘over‘);
        },function(){
            $(this).removeClass(‘over‘);
            $(‘.table tr:even‘).addClass(‘alt‘);    //偶数行变色
        });

    });