在ASP.NET MVC中实现“记住我”功能

I'm trying to implement a "remember me" feature to my login form. I am using ASP.NET MVC as my web application. I managed to get the cookie stuff working, but I failed to automatically login the user in case he/she checked the remember me checkbox before. I know what the problem is but I do not know how to solve it. I'm trying to implement a "remember me" feature