Login class available in different classes

[eluser]mvdg27[/eluser]
Hi,

I'm new to CodeIgniter, but so far I really like what I see. I'm now working on my first "test application" and run into a little problem.

I started of with expanding the welcome controller, adding some functions to it and displaying several items in the view. Now I want to add a little login form to the page. In itself this is not difficult and I got that working.

However I'd like to create another class (e.g. Blog) now, and still have the login functionality available. Again adding the form to the view is not the problem (using a template for it). But it doesn't seem to make sense to reproduce the login code in the Blog class.

Actually I'd like to create a different class, especially for the login part. My question now is, where to place that class, while still conforming to CodeIgniters standards and how to make that class available in both Welcome and Blog?

Thanks in advance!
-Cheers, Michiel