As I was not able to access the Session object  and you told me thats bcoz of the hrefs which open the window in a different session, I have replaced all the hrefs with winow.open - javascript function. It means :

I replaced:
"<li>Continents</li>

with:
<li>Continents</li>

After that I was able to access my session object. But now my problem is that the "Continents" word on the page doesn't appear as a link.. Is there any work around for this so as to get "Continents" link and keep the same session.