No view updating after viewmodel been changed - asp.net-mvc-3

Question

can't find whats wrong and can't find answer anywhere. My problem is my view not updated after view model have bean changed
ViewModel:
public class OrderView
{
public Customer Customer { get; set; }
public Order Order { get; set; }
}
public class Order
{
public int OrderId { get; set; }
public int CustomerId { get; set; }
public List<string> DomenNames { get; set; }
}
public class Customer
{
public int Id { get; set; }
public string Name { get; set; }
public string Telephone { get; set; }
public string Email { get; set; }
}
Controller:
private OrderView ov;
public ActionResult Index()
{
return View(ov);
}
[HttpPost]
public ActionResult Index(OrderView model, FormCollection collection) {
return View("done");
}
public ActionResult BlankEditorRow(OrderView model) {
ov = model;
ov.Order.DomenNames.Add("");
return View("Index",ov) ;
}
View:
#using (Html.BeginForm("Index","Order",FormMethod.Post, new {id = "createOrder"})) {
#Html.ValidationSummary(true)
<fieldset>
<legend>Order</legend>
<div class="editor-label">
#Html.LabelFor(model => model.Order.DomenNames)
</div>
#for(int i = 0; i < Model.Order.DomenNames.Count; i++) {
<div>
#Html.EditorFor(item => item.Order.DomenNames[i])
</div>
}
<button type="button" id="b1" onclick="setallert()" >Click me</button>
...
and script:
<script type="text/javascript">
function setallert() {
$.ajax({
url: "Order/BlankEditorRow",
data: $('#createOrder').serialize(),
cache: false,
success: function (data) {
...?
}
});
};
</script>
it goes fine to pass model to controller and while debugging through view I can see that model is changed, but in some case it nothing happen in view. It looks like old model is in place.

Answer 1

I have solved my problem. I post my solution in case some one need it:
Controller:
public ActionResult BlankEditorRow(OrderView model) {
model.Order.DomenNames.Add("");
return PartialView("Index", model) ;
}
View:
<div class="editor-label">
#Html.LabelFor(model => model.Order.DomenNames)
</div>
<div id="tt">
#{Html.RenderPartial("OrderDN", this.Model);}
</div>
<button type="button" id="addBtn">Click me</button>
Script:
$("#addBtn").click(function () {
$.get('#Url.Action("BlankEditorRow", "Order")', $('#createOrder').serialize(), function (res) {
document.getElementById("tt").innerHTML = res;
});
})
I hope it will be useful to someone