Kill session on popup close until the closing of browser
<p>I want to show a popup about browser compatibility to the users visiting my website. I have used the popup in about 5 pages and it would be annoying for the users to see the same popup for more than once when they visit my website.  So I am thinking to use a session and kill it when the user closes the poup. IT should not be shown until the browser is restarted. Could someone tell me how it can be done. I know what can be done but not how? Thanks a lot inadvance!!</p>
