$(function(){
     　　　　$.ajax({
                    type: 'post',
                    url: 'aaa/bbb.do',
                    contentType: 'application/json;charset=utf-8',
                    data: '{"name": "uname", "age": 18}',
                    success: function (data) { //返回json結果
                        alert(data);
                    alert(data.name);
                    }
           });   
});