Hello to every one !!

I m working on asp application . and i embed 3rd party Newsletter in it,
when user log in in the system ..the session created and when user click on Newsletter page.it redirected to first page of newsletter applciation. ..but i need to check..if the session destroy the page should not redirected to newsletter .page .

(newsletter application has couples of pages) and integrate in the application
should i suppose to check session is present or not on each page or should i supose to follow another technique for this purpose.......

do let me know if one need further clarification

looking forward for reply ASAP..

Thanks