each html form has a hidden form_id and counter_id
counter_id on the client side is generated through javascript code
on the server the form_id and counter_id is stored in the session
after sending the html form the server checks the form_id and counter_id
git-svn-id: svn://ttmath.org/publicrep/winix/trunk@1116 e52654a7-88a9-db11-a3e9-0013d4bc506e
