Need to access a variable after session timeout.

Question

If I need to access a variable after session time out where should I store the variable.

Added session time out in web.config as

  <sessionState mode="InProc" timeout="15" /> 

  using targetFramework="4.5" 

 after session time out i need to access  a variable .so please let me know  where to store variable (Session State,Application State).please give a example to store and access.

for example

if(HttpContext.Current.Session["IsLoggedIn"] == null)

{

      //Here i need to check the variable  after session  time out

     if(Isadminlogin) {

         Response.Redirect("./adminlogin.aspx");

       }else{

          Response.Redirect("./memberlogin.aspx");

       } 

}