                        课程
                    
                        /前端开发
                        
                            /jQuery
                        
                        /jQuery基础课程

请帮忙看看哪里错了。。

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>练习题</title>
<script src="http://libs.baidu.com/jquery/1.9.0/jquery.js" type="text/javascript"></script>
</head>
<body>
   <table id="list">
     <caption>学生情况表</caption>
     <thead>
         <tr>
             <th>学生姓名</th>
             <th>学生年龄</th>
             <th>学生性别</th>
             <th>学生班级</th>
         </tr>
     </thead>
     <tbody>
         <tr align="center">
             <td colspan="4"><input type="button" value="点击加载" id="a"></td>
         </tr>
     </tbody>       
   </table>
    <script>
    
        var student = [
           {"name":"路易斯","age":"26" ,"class":"高三（12）班","sex":"男"},
           {"name":"法兰克","age":"22" ,"class":"高二（11）班","sex":"男"},
           {"name":"张  三","age":"29" ,"class":"高三（15）班","sex":"女"},
           {"name":"李  四","age":"18" ,"class":"高三（08）班","sex":"男"},
           {"name":"约  翰","age":"21" ,"class":"高三（02）班","sex":"女"},
		   {"name":"王子李","age":"27" ,"class":"高三（05）班","sex":"男"},
		   {"name":"王二小","age":"26" ,"class":"高三（09）班","sex":"女"},
           ];
    $(function displayList(){
        $("#a").bind("click",function(){
        $("#list").find("tbody").empty();
        $.each(student,function(index,student){
        $("#list").find("tbody").append("<tr><td>"+student.name+"</td><td>"+student.age+"</td><td>+"student.sex+"</td><td>"+student.class+"</td></tr>");
        });
    });
    })
    
        
    </script>
    
</body>
</html>

函数没有输出，在DW编辑器里代码提示错误在这一句： $("#list").find("tbody").append("<tr><td>"+student.name+"</td><td>"+student.age+"</td><td>+"student.sex+"</td><td>"+student.class+"</td></tr>");

可是我怎么看也没错误啊。。