如果在MVC 3中未经过身份验证，如何轻松重定向？

I am brand new to ASP.NET, and I'm trying to find a way to easily redirect an unauthenticated user from any page on the site to the logon page. I would prefer to not put the following code in every HTTP GET function if there is another option.I am brand new to ASP.NET, and I'm trying to fi