Custom MembershipProvider in MVC 4

[cuteharez]

I'm a starting to learn about MVC4. As first steps, I need to perform a login since a custom database with just three roles in the database.Is it realy necessary to implement a custom membership provider? I'm question this because I was reading this post and he's doing another way: http://patrickdesjardins.com/blog/asp-net-membership-with-mvc4I just need to get users from a custom database and determine the role.To determine the rule, is a quite simple. I've got two tables called Students and Teachers. Each one has its Id as is loggin Id, and the common property password.\[code\]if (db.Students.Where(x => x.StudentId == x && x.Password == y) return "student"if (db.Teachers.Where(x => x.TeacherId == x && x.Password == y) return "teacher"// does not exist\[/code\]Can you orient me about how to implement this features in ASP.NET?