GSM program code.. Help me

Good Day Everyone.. :)

Can I ask A favor to everyone? Please help me, I'm making a project "GSM Based Car Security System" I use Arduino Atmega168 and GSM module 900d.. This is my first time to make this project with GSM and I'm a newbies in arduino and I don't have any idea with GSM.. Please help me :( I need a program code, that when I send a message to the GSM the LED will light "ON" and the same time the GSM send a confirmation to the sender. Thank You for helping.. :)