序列化表单并使用POST方法使用ajax发送序列化数据

Question

I'm trying to serialize a form and send the serialized data with ajax using POST method ..

index.php

<form id ="form" class = "form">
        <input type = "text" name = "name" />           
        <input type = "number" name = "age" />
        <input type = "number" name = "id" />
        <input type = "submit" name = "submit"><br/>
</form>
<p id = "result"></p>

Jquery snippets

<script>
    $(document).ready(function(){
        $("#form").submit(function(){
            var data = $("#form").serialize();
            insertStudent(data);
            return false ;
        });
        function insertStudent(data){
            $.post("process.php" , { data : data} , function(str){
            $("#result").html(str);
            });                 
        }
   });
</script>

process.php

$ret = $_POST["data"];
echo "<br />".$ret["name"];

And now , the result is :

Notice: Undefined index: name in C:\xampp\htdocs\try.php on line 3

When i tried to echo $_POST["data"] the result is :

name=Ahmed&age=111&id=222

how can i use every name individually such as : $_POST["name"] ... $_POST["age"] ... $_POST["id"] ?