how to create static list over session in asp mvc : i should create buy basket in my website and i like to use list<int> static of id's of products that user selected but when i create this static list i 

     public static list<int> Ordered_products;

and add item to this list buy 

     Ordered_products.add(item.id);

and show the product name buy id's in Ordered_products when multi user insert to the list users can see the product hat another user insert it to the list .

how can i have static list over session?