JavaScript runtime error: Unable to get property 'domain_name' of undefined or null reference

Can Any body help on this

From View:
<pre>@Html.ActionLink("Details", "", 
     new { id = item.id },
     new { onclick = "someFunction(" + item.id + ")", 
     href = "javascript:void(0)" }) 

function someFunction(id) {

   $.ajax({
    type: 'POST',
    url: '@Url.Content("~/")Contracts/Test/',
    data: { 'id': id },       
    dataType: 'json',
    success: function (data) {
        alert(data.domain_name);
    },
    error: function (xhr, status, exception) {
            alert("Error: " + exception + ", Status: " + status);
        }
});    

public JsonResult Test(int id)
    {
        var result = (from cntrct in db.contracts where cntrct.id == id 
              select new { cntrct.domain_name, cntrct.id}).ToArray();    
        return Json(result);
    }