how to activate one day sms pack in airtel?
['Airtel to Airtel SMS. Validity. 1 Day. Activation. Dial. *166*2# Activate.', 'Airtel to Airtel SMS. Validity. 1 Day. Activation. Dial. *166*3# Activate.', 'Airtel to Airtel SMS. 400. Validity. 30 Day. Activation. Dial. *166*4# Activate.']