you can normally acess the browser session id through
var sessionid = Session.SessionID;
well the reason for you cannot acess the session id is
may be your cookies are not enabled
you can enable your cookies by following the steps given in
http://help.mybluelight.com/support/browser/msie7-cookie-enable.html
(or check for tools->internet options->privacy tab ->settings to medium.)
also for some browsers the session id changes for every postback
for that you can set the sessionid in global.aspx page and acess accordingly in your page.
refer the article http://forums.iis.net/t/1161122.aspx
hope this helps
sanjeev
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