Rather than destroy the whole session you can selectively remove individual parts of the session. To get the cart cleared and a new session id you could add in some code like this:
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.