Session variables in business logic layer in Durandal

Question

I am using a C#.NET Durandal Application.

A have a business logic layer which is a C# class library. I want to store some values in the session variable in business logic.

So whenever an ajax request comes to it, i dont have to refetch those values.

Session["val"] = "whatever"; Doesnot work, as i am not inheriting my class from PAGE class of .NET

i store data using System.Web.HttpContext.Current.Session.Add("storeSomething","my values");

but when the next ajax request comes, there is nothing in "storeSomthing" and HTTPContext.Current.Session is null.

Please help...