title: How can I check if a user exists in my Login action?
body: <p>I am starting to use the new identity management and have a simple need. When my user logs in with a wrong name it reports a password error. How can I change this so that it also checks to see if the username exists using the dbcontext method ?</p>
  
  <pre><code>    public ActionResult Login(LoginViewModel model, string returnUrl)
      {
          if (ModelState.IsValid)
          {
              // Validate the password
              IdentityResult result = IdentityManager.Authentication.CheckPasswordAndSignIn(AuthenticationManager, model.UserName, model.Password, model.RememberMe);
              if (result.Success)
              {
                  return Redirect("~/home");
              }
              else
              {
                  AddErrors(result);
              }
          }
  
          // If we got this far, something failed, redisplay form
          return View(model);
      }
  </code></pre>