# OnClientAppointmentContextMenuItemClicking

The **OnClientAppointmentContextMenuItemClicking** client-side event is called when an appointment context menu item is clicked,before RadScheduler processes the click event.

Two parameters are passed to the event handler:

* **sender** is the scheduler client object.

* **eventArgs** has the following methods:

  * **get_appointment()** - the instance of the appointment.

  * **get_item()** - the clicked menu item.

  * **set_cancel()** - used to cancel the event.

This event can be cancelled.