How to pass date from partial view to controller in MVC4?

Hi I want to pass the data from partial view to controller

My Partial view Code

@Html.Label("Area" , new { @class = "control-label" })
@Html.TextBoxFor(model => model.Area, new { @class = "form-control", type = "text" ,id ="AreaName"})
@Html.ValidationMessageFor(model => model.Area)
@Html.Label("City")
@Html.DropDownList("CityID", null, "Select", new { @class = "form-control " })

<script src="~/Scripts/jquery-1.10.4-ui.min.js"></script>
<link href="~/Content/jquery-ui-1.10.4.custom.min.css" rel="stylesheet" />
<script src="~/Scripts/jquery-ui-1.8.24.min.js"></script>
<script type="text/javascript">

function SaveArea()
{

var Area = $("#AreaName").val();
var CityID = $("#CityID").val();
alert(Area);
var AreaAdd = { "AreaName": '' + Area + '', "CityID": CityID };
alert(AreaAdd.AreaName);
alert(AreaAdd.CityID);
$.post("/Customer/AddAreaInfo", AreaAdd,
function (data) { if (data == 0) { location = location.href; } }, 'json').success(function (data) {
alert("sucess");
//window.close();
});
}
</script>

My Model(CustomerViewModel)

public Nullable<System.Guid> AreaID { get; set; }
public string Area { get; set; }
public Nullable<System.Guid> CityID{ get; set; }
public string City { get; set; }

My Controller

public ActionResult AreaPartialView()
{
ViewBag.CityID = new SelectList(db.Cities, "CityID", "DisplayName");
return View("AreaPartialView");
}
[HttpPost]
public ActionResult AddAreaInfo(CustomerViewModel objareaVM)
{
var objAreaID = Guid.NewGuid();
ViewBag.CityID = new SelectList(db.Cities, "CityID", "DisplayName", objareaVM.CityID);

var ObjArea = new Area()
{

AreaID =objAreaID,
DisplayName = objareaVM.Area,
PrintName = objareaVM.Area,
CityID = objareaVM.CityID,
IsActive = true,
IsDeleted = false,
CreatedDate = DateTime.Now,
EditedDate = DateTime.Now,
LastActiveOn = DateTime.Now,
RowID = Guid.NewGuid(),
CreatedSessionID = Guid.NewGuid(),
EditedSessionID = Guid.NewGuid(),
OfflineMode = false,
OfflineID = Guid.NewGuid()
};
db.Areas.Add(ObjArea);
db.SaveChanges();
ModelState.Clear();
return Json("Customer", JsonRequestBehavior.AllowGet);

}

When i enter the details it get all the values in j query function it getting the value in
var Area = $("#AreaName").val();
var CityID = $("#CityID").val();

and also in

var AreaAdd = { "AreaName": '' + Area + '', "CityID": CityID };

and showing all alert message with values there is no problem in getting the values in j query function . The problem is in passing these values to controller the Area Value will be null but nit CityID. This is my issue . I am facing this issue from long time . please any one help me to resolve this issue..

Advance thanks..