This is a detailed tutorial that explains how you can extend the functionality of DHTMLX Scheduler .NET web-control to create an online room booking calendar or other reservation service. By following this tutorial you'll get a booking application with the following features: All users should be authorized to add events to the calendar; Every user has access only to his events, which he can modify or delete; Expired calendar events can't be deleted or edited; Only one room for one event can be selected from a drop-down list; Different event colors are set for different users; Agenda and Room views in addition to Week and Month views.