How can I pass arraylists from a web form to another ?

I'm doing a hotel reservation website and I have implemented 3 arraylists that contain the clients room types, room number and total price.
I pass these arraylists to 3 other static arraylists in an AppCode class. I made those static since that's the only way to keep the values in there. My problem is that this works for a single browser, but whenI try with multiple browsers, and insert data into any of the arraylists, bcos they are static they affect other client browser requests.
I need to know how I can prevent this or another method of passing arraylists to other web forms taking note of sessions.