logout redirect to index page?

To expand on my previous post:
I want to put the login form on the blog index page above the calendar. Non-logged in users see the enter your username and password boxes. Logged in users see “Welcome username”,” post a new entry”, and “logout”.
I have the hack working, except for the redirects.
How can you stop the redirect to the admin post a message page when you login? How can you stop the redirect to the log in page when you logout? When the user logs in and out, I want them to stay on the current page (either the index page or archive page.)
Thanks