session timeout - how does it work?

[Raj Puri]

I set session time out to 30 minutes in web.xml file using:

session-config>30</session-config>

And I have a code like this in submit button:
<% if (!session.isNew()) { %>
alert("Session timeout, please close browser and restart session");
return false;
<% } %>

Seems no matter what the browser thinks it is an old session going on. I am
doing JSP page and want to set timeout in web.xml and have that message show up if noactivity for 30 minute. I have tried closing, restarting browser/Tomcat etc.

How can i do this?

[Tim Baker]

your logic seems odd, surely it should be

if session is new show message "session expired"

[Surasak Leenapongpanit]

Should be..

<% if (session.isNew()) { %>
alert("Session timeout, please close browser and restart session");
return false;
<% } %>