LCD control by Phone Calls

Projects General Guidance
1

Hi, I am

I have a problem here, I have the Arduino Uno Connected to GPRS SHIELD SIM900 and a 16X2 LCD display.

I want the LCD to print "Authorized" with the caller name when a call is made from a number in the contact list.
Calling from any other number must print "Unauthorized" with the caller number.

Thanks in advance.

2

It doesn't appear that shield accesses Caller ID information.