Robert, I'm wandering dangerously off-topic, but as a retired police officer, I can tell you that the 911 system is the most over-rated bit of technology the 20th century came up with. The fact that you can get a read-out as to where a call is coming from is a fine improvement, but otherwise it's still a switchboard manned by.......well, never mind.<< May I say 'THANK YOU' although your retired.