public IActionResult Index(string activeConf = "all", string activeDiv = "all")
        {
            var session = new CustomerSession(HttpContext.Session);

            session.SetActiveConf(activeConf);
            session.SetActiveDiv(activeDiv);

            var model = new Customer
            {
                Name        = activeConf,
                Email       = activeDiv,
                Conferences = context.Conference,
                Divisions   = context.Divisions
            };

            IQueryable <Registration> query = context.Registrations;

            if (activeConf != "all")
            {
                query = query.Where(
                    t => t.Conference == activeConf.ToLower());
            }
            if (activeDiv != "all")
            {
                query = query.Where(
                    t => t.Division == activeDiv.ToLower());
            }
            model.Registrations = (System.Collections.Generic.List <Customer>)query;

            return(View(model));
        }