List is not persisting through updatemodel - asp.net-mvc

Question

My generic list of products won't persist on the Post if I use UpdateModel but if I pass the ViewModel in as a parameter to my post action method it works? How can I get it to work through UpdateModel way?
I'm using asp.net fx3.5 mvc 1.0
Model
namespace PostingGenericListAndUpdateModel.ViewModels
{
public class Product
{
public string Name { get; set; }
public bool IsSelected { get; set; }
}
public class ProductViewModel
{
public int OrderId { get; set; }
public List<Product> Products { get; set; }
public ProductViewModel()
{
Products = new List<Product>();
Products.Add(new Product() { Name = "Widget 1", IsSelected = false });
Products.Add(new Product() { Name = "Widget 2", IsSelected = false });
}
}
}
View
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
<h2>Index</h2>
<% using (Html.BeginForm())
{ %>
<% for (int i = 0; i < 2; i++)
{ %>
<%= Model.Products[i].Name %> <%= Html.CheckBox("Model.Products[" + i + "].IsSelected") %>
<% } %>
<input id="Submit1" type="submit" value="submit" />
<% } %>
</asp:Content>
Controller
public ActionResult Index()
{
ViewData["Message"] = "Welcome to ASP.NET MVC!";
ProductViewModel model = new ProductViewModel();
return View(model, new string[] { "OrderId", "Products" });
}
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Index(FormCollection form) //It will work if i accept the view model
{
ProductViewModel model = new ProductViewModel();
UpdateModel(model);
return View(model);
}

Answer 1

I see no reason for this parameter 'string sender'. Why do you need it?
The usual way to do this is indeed, by accepting the view model as a parameter to your Post method.
This is the way MVC passes the information from the view to your controller.
Your Post method line should be:
public ActionResult Index(ProductViewModel model)