MVC3 how to add dynamic values to shopping cart

I have been following a guide to create a shopping cart in MVC3.

http://开发者_如何转开发mvcmusicstore.codeplex.com/

What i would like to do is to add additional values to the page where a user can add to cart. I want the option to select qty and size.

   @Html.ActionLink("Add to cart", "AddToCart",
                    "ShoppingCart", new { id = Model.Id }, "")

If a user changes the qty or size then the Model.ID value needs to be changed in this link. How do i refresh the page and do this dynamically?

In my current project, we have a quantity next to the "Add to Cart" button. When the "Add To Cart" button is clicked, I get the url, add the quantity to it, and then send an ajax request back to the server.

$('#AddToCartLink').click(function() {
            var link = $(this).attr('href') + '?quantity=' + $(this).siblings('.Quantity').val();

            $.ajax({
                url: link,
                type: "POST",
                success: AddToCartSuccess,
                error: AddToCartFailure
            });

            return false;

        });

HTML for Add to Cart button and Quantity:

<div class="DetailAddToCart">
    Qty:
    <input type="text" value="1" class="Quantity" id="Quantity" />&nbsp;
    <a id="AddToCartLink" href="@Url.Action("Add", "Cart", new {id = Model.EquipmentModelId})">
        <img src="/Content/Images/add_to_cart.png"alt="Add to Cart" /></a>
</div>