School project : GPS tracker

Hello,

For a school project, I need to make a GPS tracker with Arduino to put it in a suitcase. I find a tutorial to help : https://www.cooking-hacks.com/projects/arduino-realtime-gps-gprs-vehicle-tracking/

The problem is that I have a shield with a SIM808 instead of a SIM908 and the Arduino code don't seems to work, when I call the tracker, nothing is happening. Is that comes to the fact that this is a SIM808 instead of a SIM908 (if yes, can you tell me what I need to change) or do I do something wrong ?

Can you help me ?

Thank you in advance !

PS : sorry if my english is bad