JavaScript Editing - How would you improve this?

CustomerController.cs

public class CustomerController : Controller
{
    public CustomerRepository Repository = new CustomerRepository();

    public ActionResult Index()
    {
        return View();
    }

    public JsonResult List()
    {
        return Json(Repository.All(), JsonRequestBehavior.AllowGet);
    }

    public JsonResult Get(int id)
    {
        return Json(Repository.Get(id), JsonRequestBehavior.AllowGet);
    }

    [HttpPost]
    public JsonResult Add(Customer customer)
    {
        Repository.Save(customer);
        return Json(customer);
    }

    [HttpPost]
    public JsonResult Edit(Customer customer)
    {
        Repository.Save(customer);
        return Json(customer);
    }

    [HttpPost]
    public JsonResult Delete(int id)
    {
        Repository.Delete(id);
        return Json(true);
    }
}

Index.html

<h2>Customer editor</h2>

<table>
  <thead>
    <tr>
      <td>Id</td>
      <td>First</td>
      <td>Last</td>
      <td>Actions</td>
    </tr>
  </thead>

  <tbody id="customers_table_body" />
</table>

<a href="#" class="add-customer">Add</a>

<script id="edit_dialog_template" type="text/x-jquery-tmpl">
  <div title="Customer details">
    <div style="color: red;" id="error_details" />
    <div>First name: <input type="text" id="customer_first_text" value="${FirstName}" /></div>
    <div>Last name: <input type="text" id="customer_last_text"  value="${LastName}" /></div>
  </div>
</script>

<script id="customer_template" type="text/x-jquery-tmpl">
  <tr>
    <td>${Id}</td>
    <td>${FirstName}</td>
    <td>${LastName}</td>
    <td><a href="#" class="edit-customer" data-id="${Id}">Edit</a> <a href="#" id="delete_customer">Delete</a></td>
  </tr>
</script>

<script type="text/javascript" src="/Views/Customer/Index.js"></script>

<!-- Will be set via CSS someday -->
<div id="loading" style="position: absolute; left: 0; top: 0; width: 100%; height: 100%; background: #f00; opacity:0.4">
  <div style="text-align: center; vertical-align: middle; height: 100%">
    Please wait...
  </div>
</div>

Index.js

$(function ($) {
    var customersTableBody = $("#customers_table_body");

    $(function () {
        loadCustomers();
        
        $("a.add-customer").click(function (e) {
            e.preventDefault();
            addCustomer();
        });

        $("#customers_table_body a.edit-customer").live('click', function (e) {
            var id = $(this).data("id");
            e.preventDefault();
            $.getJSON("/Customer/Get/" + id, null, function (json) {
                editCustomer(json);
            });
        });
    });

    function loadCustomers() {
        $.getJSON("/Customer/List", null, function (data) {
            customersTableBody.empty();
            $("#customer_template")
                .tmpl(data)
                .appendTo(customersTableBody);
        });
    };

    function addCustomer() {
        var customer = {};
        
        showDetailsDialog(customer, function (result) {
            $.post("/Customer/Add", customer, function (json) {
                if (json.ErrorMessage !== undefined) {
                    result.error(json.ErrorMessage);
                    return;
                }
                result.success();
            });
        });
    };

    function editCustomer(customer) {
        showDetailsDialog(customer, function (result) {
            $.post("/Customer/Edit", customer, function (json) {
                if (json.ErrorMessage !== undefined) {
                    result.error(json.ErrorMessage);
                    return;
                }
                result.success();
            });
        });
    };

    function showDetailsDialog(customer, onSave) {
        var dialog = $("#edit_dialog_template").tmpl(customer);
        dialog.dialog({
            modal: true,
            buttons: {
                "Save": function () {
                    customer.FirstName = $("#customer_first_text", dialog).val();
                    customer.LastName = $("#customer_last_text", dialog).val();

                    onSave({
                        success: function () {
                            dialog.dialog("close");
                            loadCustomers();
                        },
                        error: function (details) {
                            $("#error_details", dialog).html(details);
                        }
                    });
                }
            }
        });
    };
});