jQuery的负载从JSON转换

I'm creating a very simple chatbox in Zend Framework via Jquery and I'm loading the content to the $('#outputArea') which is essentially a div with $.load(), but i get a json object and i need to extract only a message value.What I get with the $.load() is this:

[
    {
        "id": "1",
        "messages": "message 1"
    },
    {
        "id": "2",
        "messages": "message 2"
    },
    {
        "id": "59",
        "messages": "d"
    },
    {
        "id": "60",
        "messages": "w"
    },
    {
        "id": "61",
        "messages": "fff"
    },
    {
        "id": "62",
        "messages": "d"
    },
    {
        "id": "63",
        "messages": "df"
    },
    {
        "id": "64",
        "messages": "dfs"
    },
    {
        "id": "65",
        "messages": "dw"
    },
    {
        "id": "66",
        "messages": "dw11"
    },
    {
        "id": "67",
        "messages": "dw112"
    },
    {
        "id": "68",
        "messages": "111"
    },
    {
        "id": "69",
        "messages": "111"
    },
    {
        "id": "70",
        "messages": "dd"
    },
    {
        "id": "71",
        "messages": "sddd"
    },
    {
        "id": "72",
        "messages": "

"
    },
    {
        "id": "73",
        "messages": "ss"
    }
]

How can I do that? Thank you. Here is the jquery code:

$(document).ready(function(){
$('#outputArea').load('/index/index');
$('#chat').submit(function(){
    var message = $('#message').val();
    if(message === ''){
        $('#error-message').css('display','inline');
        return false;
    }
    $.post('/index/index',{'message':message},function(data){
            $('#error-message').css('display','none');
            var n = data.length;
            $('#outputArea').append('<div>' + data[n-1].messages + '</div>' + '<br />');    
            console.log(data);
        },'json');

     return false;
  });                  
});

and the php index controller part responsible for parsing JSON:

if($this->_request->isXmlHttpRequest()){
        $this->_helper->viewRenderer->setNoRender();
        $this->_helper->getHelper('layout')->disableLayout();
        $model = new Application_Model_DbTable_Chat();
        $data = $this->_request->getParam('message');
        //$data = json_decode($data);
        $model->createPost($data);
        $json = $model->fetchAll();
        header('Content-type:application/json');
        //print_r($json);
        foreach ($json as $key => $value) {

        }
        echo $this->_helper->json->sendJson($json);
    }

This is how you can iterate through JSON array and get the respective key and their values.

for(var i in data)
{
  var message = data[i].message;

}

I think you can proceed further.