This is probably again a newbie question.
When I create an ASP.NET MVC2 application, an Account Controller with an Action LogIn is created like this:
[H
Yeah redirecttoaction but provide an error message with it in the tempdata so you should do something like this
TempData["errorMsg"] = "incorrect values provided";
return RedirectToAction("Index", "Home")
Of course in the main index you should have a div that displays the message
<%= html.Encode(TempData["errorMsg"]) %>
EDIT I see you want to maintain the modelstate that might be a problem but what you could do is pass the modelstate in the index action or pass the modelstate object in the tempdata. What you can do then is check if a there are modelstate errors in the object and if there are check the field and add the error to the right field.