The OnClientReminderTriggering client-side event handler is called when an appointment reminder has been snoozed by the user,before the command is sent to the server.
Two parameters are passed to the handler:
sender, the scheduler client object;
eventArgs, with three properties:
get_appointment() - the instance of the appointment.
get_reminder() - the reminder.
set_cancel() - used to cancel the event.
This event can be cancelled.