ASP.NET MVC2 Edit action is adding a new entry to the database

Question

Good morning, I'm learning MVC using the music store examples on the www.asp.net/mvc page, and I am having a problem with my edit action adding a new entry into the database instead of updating the existing entry. Here is my Edit action and the HTTPPost Edit.

//
        // GET: /HomeScroller/Edit/5

        public ActionResult Edit(int id)
        {
            var viewModel = new HomeScrollerViewModel()
            {
                ScrollerLink = dataContext.ScrollerLinks.Single(s => s.SlideID == id)
            };

            return View(viewModel);
        }

        //
        // POST: /HomeScroller/Edit/5

        [HttpPost]
        public ActionResult Edit(int id, FormCollection formValues)
        {
            var scrollerLink = dataContext.ScrollerLinks.Single(s => s.SlideID == id);

            try
            {
                UpdateModel(scrollerLink, "ScrollerLink");
                dataContext.SubmitChanges();

                return RedirectToAction("Index");
            }
            catch(Exception ex)
            {
                var viewModel = new HomeScrollerViewModel()
                {
                    ScrollerLink = scrollerLink,
                    HasError = true,
                    ErrorMessage = ex.Message
                };

                return View(viewModel);
            }
        }

To give a little more background on what I am doing, I have a shared template for my Edit/Create views, and on that shared template I have a jQuery popup with a form for uploading an image. This "HomeScroller" plays a slideshow on the homepage, and I've made a back end for the admin to come in and create new slides, edit, and delete them. The other issue I am having is that when I upload an image using that second form, the main form is cleared on the post back. How do I maintain the data in those fields? Thanks.

EDIT: Here is the code for my update action

        [HttpPost]
        public ActionResult Upload(HttpPostedFileBase file, FormCollection formValues)
        {
            HomeScrollerViewModel viewModel;
            Regex imageFilenameRegex = new Regex(@"(.*?)\.(jpg|jpeg|png|gif)$");
            if (file.ContentLength > 0)
            {
                if (!imageFilenameRegex.IsMatch(file.FileName))
                {
                    viewModel = new HomeScrollerViewModel()
                    {
                        ScrollerLink = new ScrollerLink(),
                        HasError = true,
                        ErrorMessage = "Image must be .jpg, .jpeg, .png, or .gif"
                    };
                }
                else
                {
                    string filePath = Path.Combine(HttpContext.Server.MapPath("../Uploads"), Path.GetFileName(file.FileName));
                    file.SaveAs(filePath);
                    viewModel = new HomeScrollerViewModel()
                    {
                        ScrollerLink = new ScrollerLink()
                        {
                            ImageUrl = "../Uploads/" + file.FileName

                        }
                    };

                    return View("Create", viewModel);
                }
            }
            else
            {
                viewModel = new HomeScrollerViewModel()
                {
                    //ScrollerLink = scrollerLink,
                    HasError = true,
                    ErrorMessage = "Image is empty!? Try Again"
                };
            }
            return View("Create");
        }

Answer 1

I feel retarded for this one. In my update action, I am returning to the "Create" view, which is wrong if I am working with the "Edit" view, this is why it was adding a new object instead of modifying the existing. Also - I stored my viewmodel using TempData["HomeScrollerViewModel"] and passed my data around that way. Problem solved.