                        课程
                    
                        /前端开发
                        
                            /JavaScript
                        
                        /JavaScript进阶篇

请问下，这里哪里错了呢

<!DOCTYPE  HTML>
<html >
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>流程控制语句</title>
<script type="text/javascript">

 var students=new Array();
 students=[
     ['小A','女',21,'大一'],
     ['小B','男',23,'大三'],
     ['小C','男',24,'大四'],
     ['小D','女',21,'大一'],
     ['小E','女',22,'大四'],
     ['小F','男',21,'大一'],
     ['小G','女',22,'大二'],
     ['小H','女',20,'大三'],
     ['小I','女',20,'大一'],
     ['小J','男',20,'大三']
     ]；
 
for(var i=0;i<students.length;i++)
    {
        switch(students[i][1])
            {
                case "女":
                    switch(students[i][3])
                        {
                            case "大一":
                            document.write(students[i][0] + "是一个" + students[i][3] + students[i][1] + "生" + "<br>");
                            break;
                        } 
                break;
            }
                
    }


</script>
</head>
<body>
</body>
</html>