def sms_subscription():
    contact_num = request.values.get('From')
    response = request.values.get('Body')
    resp = MessagingResponse()

   #NEW SUBSCRIBERS
    if response.lower() == 'memphis':
       with open('Subscriber_List.csv', 'r+') as subscriber_list:
           subscriber_list_writer = csv.writer(subscriber_list)
           for contact in subscriber_list:
               if contact == contact_num:
                   resp.message("Your already subscribed")
                   return str(resp)

               else:
                   subscriber_list_writer.writerow([contact_num])
                   resp.message("Thanks for subscribing to our local coupon book. As we get new deals, we'll notify via SMS. To opt-out reply 'STOP'")
                   return str(resp)

    else:
        resp.message("Be sure to check spelling and for spaces and try again.")
        return str(resp