How to maintain session time out in parent window and popup windows

[ayyappan Bas]

I am developing an application where there are two windows named "parent window" and "popup window".when i click a button from parent window it opens a popupwindow where i developed a application for writing a exam. The session time out i had set as 30 minutes in web.xml.When i click the button from parent window and popup window opens and exam starts and i had set exam time as 60 minutes,but after 30 minutes the session gets expired in popup window since the session time out in web.xml is 30 minutes.This is where i am encountering the problem because of this i am not able to write the exam.How can i solve this problem and i dont want to change the session time out in web.xml, as the exam time changes for each exam?

[Bear Bibeault]

You'll either need to increase the session time-out value. or add an Ajax "pinger" to the exam pages to keep the session active by making requests back to the server at regular intervals.