在ASP.NET MVC，初学者中定时用户访问

In ASP.NET MVC, what is a good way (the preferred way??) to time how long a user has been on a specific page? For example, I want the user to select something and then only allow the user to do something for 30 seconds. Good links or a reference to a page of a book would be much appreciated.In ASP.NET MVC, what is a good way (the preferr