JSON pass null value to MVC 4 controller in IE9

JSON pass null value to MVC 4 controller in IE9

I got some problem while posting JSON data into MVC 4 controller.
Below method is working fine in Firefox but unfortunately failed in IE 9
The JavaScript :
var newCustomer = {
CustName: $("#CustName").val(),
CustLocalName: $("#CustLocalName").val(),
CustNumber: $("#CustNumber").val(),
CountryID: $("#SelectCountry").val(),
City: $("#City").val()
};
$.ajax({
url: '@Url.Content("~/CustomerHeader/CreateCustomerHeader")',
cache: false,
type: "POST",
dataType: "json",
contentType: 'application/json; charset=utf-8',
data: JSON.stringify(newCustomer),
success: function (mydata) {
$("#message").html("Success");
},
error: function () {
$("#message").html("Save failed");
}
});
and this is my controller :
public JsonResult CreateCustomerHeader(CustomerHeader data)
{
try
{
if (!ModelState.IsValid)
{
return Json(new { Result = "ERROR", Message = "Form is not valid! Please
correct it and try again." });
}
RepositoryHeader.Update(data);
return Json(new { Result = "OK", Record = data });
}
catch (Exception ex)
{
return Json(new { Result = "ERROR", Message = ex.Message });
}
}
the "data" variable as in public JsonResult
CreateCustomerHeader(CustomerHeader **data**) is getting NULL but while
using FireFox it holds the correct value.