Cookie Authentication questions

[Netnoobie]

I have a cookie set up to be created when logging in that persists for the session. Now I have two questions:

- Is it possible to send other items to this authentication cookie as defined in the webconfig file? I have an ID being returned that shows the users level of rights. Can I write this to the same cookie, or do I have to also create another one after writing the authentication cookie?

- When using an authentication cookie, do I have to call IsAuthenticated at the beginning of every page? Or since the authentication is set up in the webconfig file, will it automatically check upon each page load?

Thanks!