*5005*25371# - Use it to check whether the alert system is working or not.
*5005*25370# - This one disables the alert system
*3282# - Shows the use of information info.
*#61# - Shows the number of missed calls
*646# (Postpaid) - Shows the available calling minutes
*225# (Postpaid) - Shows the Bill Balance
*777# (Prepaid) - Shows the available balance.