Jquery把获取到的input值转换成json

<!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> jquery把获取到的input值转换成json</title>
 <meta http-equiv="Content-Type" content="text/html;charset=UTF-8" />
 <link rel="stylesheet" type="text/css" href="" />
 <style type="text/css">
 .box{width:500px;height:500px;border:1px solid #e5e5e5;}
 </style>
 <script type="text/javascript" src="jquery-1.7.1.min.js"></script>
 </head>
 <body>
 <div class="box">
    姓名：<input type="text" value="" name="username" /> <br/><br/>
    年龄：<input type="text" value="" name="age" /> <br/><br/>
    生日：<input type="text" value="" name="birth" /> <br/><br/>
    城市：<input type="text" value="" name="city" /> <br/><br/>
    省份：<input type="text" value="" name="provicen" /> <br/><br/>
    性别：<input type="text" value="" name="sex" /> <br/><br/>
    <input type="button" value="提交" class="comment">
 </div>
 <script type="text/javascript">
  $(document).ready(function(){
    $(".comment").click(function(){
      parArr = {};
       var username = $('input[name=username]').val().replace(/(^\s*)|(\s*$)/g, "");
       parArr.username = username;
       var age = $('input[name=age]').val().replace(/(^\s*)|(\s*$)/g, "");
       parArr.age = age;
       var birth = $('input[name=birth]').val().replace(/(^\s*)|(\s*$)/g, "");
       parArr.birth = birth;
       var city = $('input[name=city]').val().replace(/(^\s*)|(\s*$)/g, "");
       parArr.city = city;
       var provicen = $('input[name=provicen]').val().replace(/(^\s*)|(\s*$)/g, "");
       parArr.provicen = provicen;
       var sex = $('input[name=sex]').val().replace(/(^\s*)|(\s*$)/g, "");
       parArr.sex = sex;
       var params = JSON.stringify(parArr);
       alert(params);
    });
  });
 </script>
 </body>
</html>