Intimation to IT dept after paying demand amount

Hello,

    Recently i received a demand notice from IT dept of 19000/- Rs for assesment year 2008-09.For which i checked with a Finance person and he found that there was a tax calculation mistake from my side.So i paid the Demand in total from e-filing demand under these details:-

Now i want to know how to intimate the IT dept for the same, what would be the procedure and what would be the format of that letter of intimation and also the mode of communication (registered post etc) ?

Please note - I made the payment within 15 days of receiving the demand notice.

Thanks in Advance !!

Gaurav