You will need to put them in a form (possibly as INPUT TYPE=hidden) and the form action is an ASP page that reads the form values and assigns them to the session vars.
You see ASP runs on the server, JavaScript runs on the client. Once the page is on the client the only way to run server side scripts (like ASP) is to call another web page.
Hope this helps, Einstein47
(Love is like PI - natural, irrational, endless, and very important.)