Assign a Role manually

Dear All,

I need your help on something:

I have my own database with my own table and stored procedures for handling users. I also have my pages for creating, editing and deleting users. And I apply my own login technique.

My question is, what method do I use to assign a role to the user after he logs in so I can use the web.config security options that are related to a certain role? (i.e.; going to a certain folder or a page).

I have already found the function that tells the ASP.NET that the user is valid. Now I need to find the function that te ...