无法在客户端编辑json文件

我想用javascript编辑一个json文件。该文件为"client"。Json"，位于本地系统，并且只能在本地系统上进行修改。我正在使用表单创建新的客户端详细信息，我希望这些详细信息被附加到json文件作为对象。

 {"clients":[
        {
            "name":"xxxx",
            "team":"yyy",
            "location": {
                "city":"beijing",
                "country":"china"
                        },
        "wdays":{"start":"Monday","end":"friday"},
        "whours":{"start":"9 A.M","end":"6 P.M" }
        },
        {
            "name":"xxxx",
            "team":"yyy",
            "location": {
                "city":"new york",
                "country":"usa"
                       },
        "wdays":{"start":"Monday","end":"friday"},
        "whours":{"start":"9 A.M","end":"6 P.M" }
        }
]}

下面的javascript代码是关于从表单读取数据并将该数据附加为json对象......... '

</script>
<script type="text/javascript">
    function addtojson()
    {
       var client_name=(document.getElementById("cname")).value;
       var country=document.getElementById("country").value;
       var city=document.getElementById("city").value;
       var wtimeto=document.getElementById("wtimeto").value;
       var wtimefrom=document.getElementById("wtimefrom").value;
       var wdayto=document.getElementById("wdayto").value;
       var wdayfrom=document.getElementById("wdayfrom").value;
    jQuery.getJSON('client.json')
  .done(function(data) {
  var cobj=new Object();
  cobj.name=client_name;
  cobj.team="YYY";
  cobj.location=new Object();
  cobj.location.city=city;
  cobj.location.country=country;
  cobj.wdays=new Object();
  cobj.wdays.start=wdayto;
  cobj.wdays.end=wdayfrom;
  cobj.whours=new Object();
  cobj.whours.start=wtimeto;
  cobj.whours.end=wtimefrom;
  var myString = JSON.stringify(cobj);
  alert('I am working');
  alert(myString);
   data.clients.push(cobj);
      alert(JSON.stringify(data.clients[0]));//it gives previous first array object
      alert(JSON.stringify(data.clients[1]));//it gives previous second array object
      alert(JSON.stringify(data.clients[2]));//it gives the new appended array object
      });

return true;
} 
</script>`

虽然数据在程序中被本地修改，但json文件没有更新????????