Data value get Null in ajax action

function GetStatusDetails(id) {

$.ajax({

url: '@Url.Action("GetStatusDetails","GenerateMemo")',

type: "GET",

data: { "id": id },

datatype: "json",

contentType: "application/json; charset=utf-8",

success: function (data) {

alert(data.vcMemSubject);<-------------------------get Null

if (data != null) {

$("#signature").val(data.vcMemSigunature);

$("#subject").val(data.vcMemSubject);

$("#body").val(data.vcMemText);

}

error: function (e) {

//alert(e.data);

}

});

}

[HttpGet]

public tblMstMemo_MEM GetStatusDetails(int id)

{

try

{

if (id > 0)

{

tblMstMemo_MEM statusDetails = db.tblMstMemo_MEM.Find(id);

return statusDetails;

}

catch (Exception ex) { ex.Message.ToString(); }

return null;

}