How do I keep user login from creating a new session?

[carcomp]

I've been working on a site that uses a session variable that I created. Now i've got *most* of it working right (seems session variables are a pain in the arse) but I've got a new problem.

If you are using the site, and set my session variable (usingchat) which causes the header to not show if its 1, then you login, seems that the usingchat variable goes back to 0. Now maybe i'm not understanding this session thing, but I can't figure out why that creates a new session.

Also, is there a better way to do this? I can't use "index.php?usingchat=1" because it seems when I do, then go to some other page (like login.php) that variable is lost. I'm actually using a combination of the above AND a session variable b/c it seems like the session variable only get set once you navigate to the "next" page, but the "?" gets set on the current page.

I'm just trying to create a sitewide variable for ANY person (regardless of user or anon) that can be set to 0 or 1 AND be able to change it during stay, and stay that way until they leave my site totally, nav back to the main url.

Here is an example... go to www.quad4forums.com/test (the main "non" test url is the temp site so don't go there.

If you click the chat link, you see the new frames page, with the header on the top. THAT part works. But notice the "header variable =0" <-- thats the session. Now refresh the page. It goes to 1. whats going on?? Its like the server is taking an extra 5 seconds to set the variable. If you keep refreshing, it will change back.