Ajax retrieve JSON data and Html data from MVC Controllers in ASP.NET MVC

@{
    ViewBag.Title = "Index";
}

<h2>Ajax Demo</h2>

<div style="width: 600px; ">
    <div style="background-color:lightgray">
        <h2>Meals</h2>
    </div>
    <p>Click the button to Get Meals with an Ajax call</p>
    <input id="btnAjax" name="btnAjax" type="button" value="Get Meals" />
    <div id="meals" style="background-color:lightskyblue"></div>
    <div id="jsonResult" style="background-color:lightsalmon"></div>
</div>

<div style="background-color:lightpink;display:none;" id="updateMealDiv">
    <table>
        <tr>
            <th>Name</th>
            <th>Comments</th>
            <th>Picture</th>
        </tr>
        <tr>
            <td><input type="text" id="txtName" name="txtName" /></td>
            <td><input type="text" id="txtComment" name="txtComment" /></td>
        </tr>
    </table>
    <input type="button" value="update meal" id="btnUpdateMeal" name="btnUpdateMeal">
</div>

<script type="text/javascript">
    $("#btnAjax").click(function () {
        $.ajax({
            url: ‘/AjaxDemo/GetMeal‘,
            contentType: ‘application/html; charset=utf-8‘,
            type: ‘Get‘,
            datatype: ‘html‘
        })
        .success(function (data) {
            $("#meals").html(data);
            $("#updateMealDiv").show().appendTo($("#meals"));
        })
        .error(function (xhr, status, errorThrown) {
            alert(errorThrown);
        })
    });

    $("#btnUpdateMeal").click(function () {
        var nameVal = $("#txtName").val();
        var commentVal = $("#txtComment").val();

        $.ajax({
            url: ‘/AjaxDemo/GetJsonString‘,
            data: JSON.stringify({ name: nameVal, comment: commentVal }),
            type: ‘Post‘,
            contentType: "application/json; charset=utf-8"
        })
        .success(function (data) {
            var resultStr = "<ul><li>" + data.newName + "</li><li>" + data.newComment + "</li></ul>";
            $("#jsonResult").html(resultStr);
        })
        .error(function (xhr, status, errorMsg) {
            alert(errorMsg);
        })
    });
</script>

 public class AjaxDemoController : Controller
    {
        private Db dbContext = new Db();
        //
        // GET: /AjaxDemo/
        public ActionResult Index()
        {
            return View();
        }

        public ActionResult GetMeal()
        {
            Meal[] meals = dbContext.Meals.Where(m => m.Id <= 5).ToArray();
            return PartialView("GetMeals", meals);
        }

        public ActionResult GetJsonString(string name, string comment)
        {
            return Json(new { newName = name + "Luxuan", newComment = comment + "LLLLL" });
        }

        public ActionResult UpdateMeal(string mName, string comment)
        {
            IList<Meal> mealList = dbContext.Meals.ToList();
            Meal updatedMeal = mealList.Where(m => m.Name == mName).Single();
            updatedMeal.Name = mName;
            updatedMeal.Comments = comment;

            dbContext.SaveChanges();

            mealList = mealList.Where(m => m.Id <= 5).ToArray();
            return PartialView("GetMeals", mealList);
        }
    }