f.js

        the_event.fetch({success: function(){
            var tickets = the_event.get('tickets');
            var guestlist = new GuestList();
            for(i=0; i<tickets.length; i++){
                tickets[i]['desired_quantity'] = ko.observable(0);
                guestlist.add(tickets[i]);
            }
            console.dir(tickets);

            var viewModels = {
                ticketViewModel: new TicketViewModel(tickets),
                'guestlist': guestlist,
                personalDetailsViewModel: new PersonalDetailsViewModel()
            }
            ko.applyBindings(viewModels);
        }});