It can pretty much go anywhere in a JSP file. If you're using a JavaBean, then the getProperty tag or whatever gets the session automatically, otherwise basically with JSP's, you just call properties from the session automatically. In a Servlet, you need to declare a new Session object again and retrieve it again.
Erhm, I've so lost you haven't I?
![Stick Out Tongue :p :p](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)