Help with GSM/GPIO

[ThePATRIOT]

I need to write a program in python, for a divice with GSM modul , which send a sms (using AT commands), to few gsm numbers set in advance , if there is an input signal from external divice , and doing nothing if there is not a signal !!!
i'm a newbie , so need a real help !!!
here are few things that i figured out , but i can't solve it all

#import built-in modules

import sys
import MDM
import GPIO

#configure port I/O

r=GPIO.setIOdir( 1, 0, 0 ) #port 1 input
r=GPIO.setIOdir( 8, 0, 0 ) #port 8 input

#gsm number list

GSM_NUMBER = {}
GSM_NUMBER[0] = ("12345")
GSM_NUMBER[1] = ("23434")

#any ideas how to continue ???