how to put total page into session

hi,

 i am taking one page i.e., Credits.aspx in that page i place Multiview, in View1 i display Credits pack like 1000,2000,5000. and cost in datagrid. if user select 1000 credits pack that pack information is displayed in view2.

                    and in View2 i place one hyperlink i.e., goto shopingcart page, in that shoppingcart page i place Back button if he click
Back button, then he goes to previous selected Pack information (View2)
 
How to put Total page into session. please give a solution
 
Thanks.