Arduino GSM Shield not responding?

I’m trying to get my arduino GSM shield working with the example “Send SMS” code provided. However, when I upload and compile the program, the serial monitor displays “SMS Messages Sender” and nothing else occurs.

Would greatly appreciate it if someone can tell me where I could have gone wrong.

I’m currently using the Arduino Mega. I’m following the guide provided by the Arduino’s website with the code part of the example that comes with the Arduino program. Attached is wad is shown on the monitor.

I am using both a USB cable and an external power supply. I have performed the jumper wire modification required for the Mega to work with the shield as well.

I don’t have that shield so I am not much of a help, but :

  1. What the program should do. You can read the program and find out what it should do.
  2. There is a forum just for GSM shield. Perhaps you get better answers there because people there know the shield