To specifically answer the question:
Why does this not work?
${session.invalidate}
As pointed out, there is no implicit session variable. But even had you written it as:
it would interpreted as a accessor for the "invalidate"
property of the session scope; probably along the lines of:
Which of course isn't remotely the same as calling the invalidate() method.
[ February 09, 2005: Message edited by: Bear Bibeault ]