Guys you might be using the free gprs from AIRTEL and you might be unknown how much you have used your data limit so here is how you can check the data you have used from the airtel free GPRS 2010..
Dial *123*10#(toll free) to check the free MB in your account.
For Airtel Mumbai & Airtel Orissa
Circle its *123*6#
For Airtel Maharashtra circle its *123*7#
This works only if your Airtel connection is pre activated for free GPRS to youe account..