I am using the airtel connection since 2002 and from last year I registered myself to the www.airtel.co.in and whenever I need to see my bill details then get reply from the site is - Authentication failed. you hav used an invalid user name, password or client certificate ?

What is this client certificate ?

I really fed off with your service and I didn't received any my bill details on my E-mail ID.

Please solve the problem as early as possible.