public ActionResult Register(RegisterViewModel viewModel)
        {
            var anyUser = _repository.GetAllUserEntities().Any(u => u.Login.Contains(viewModel.Login));

            if (anyUser)
            {
                ModelState.AddModelError("", "User with this address already registered.");
                return View(viewModel);
            }

            if (ModelState.IsValid)
            {
                var membershipUser = ((CustomMembershipProvider)Membership.Provider)
                    .CreateUser(viewModel.Login, viewModel.Password);

                if (membershipUser != null)
                {
                    FormsAuthentication.SetAuthCookie(viewModel.Login, false);
                    return RedirectToAction("Index", "Home");
                }
                else
                {
                    ModelState.AddModelError("", "Error registration.");
                }
            }
            return View(viewModel);
        }
        public ActionResult Register(RegisterViewModel viewModel, HttpPostedFileBase img)
        {
            if (viewModel.Captcha != (string)Session[CaptchaImage.CaptchaValueKey])
            {
                ModelState.AddModelError("Captcha", "Incorrect input.");
                return View(viewModel);
            }

            var anyUser = _repository.GetAll().Any(u => u.Name == viewModel.Email);

            if (anyUser)
            {
                ModelState.AddModelError("", "User with this address already registered.");
                return View(viewModel);
            }
            var str = new StringBuilder();
            if (ModelState.IsValid)
            {
                if (img != null)
                    str.Append(FileHelper.SaveFileToDisk(img, Server.MapPath("~/")));
                
                var membershipUser = ((CustomMembershipProvider)Membership.Provider)
                    .CreateUser(viewModel.Email, viewModel.Password,str.ToString());

                if (membershipUser != null)
                {
                    FormsAuthentication.SetAuthCookie(viewModel.Email, false);
                    return RedirectToAction("Index", "Article");
                }
                else
                {
                    ModelState.AddModelError("", "Error registration.");
                }
                
            }
            return View(viewModel);
        }