How to stop accidental siren

Newbie forgot about motion detector and set off alarm. Fortunately I am in practice mode.I couldn't figure out how to stop the siren. Punched in my code and began hitting disarm button but no luck. Got a call but there was no way to hear anything over the siren. Finally after frantic pushing of buttons the thing stopped but I have no idea what I did, adrenaline was flowing. I see all sorts of info on settings for alarms but can't find anything about what to do after you have triggered a false alarm.