What is form 2c and 2d in delhi sales tax

During the VAT Return period w.e.f 01/04/2013

any Debit / Credit note received against purchase should be fill in FORM 2C

and

any Debit/Credit note received against sale should be fill in FORM 2D

this new feature start by the Dvat deptt because of Mismatch report due to Debit / Credit note.

HI,

DEAR, WHEN Debit/Credit note against sale should be fill in FORM 2D, IT IS NOT GETTING AUTOMATICALLY EFFECT AT THE TIME OF FILING E-RETURN. (AS DVAT/CST SHOULD DECREASE TAX )

????

WHAT SHOULD WE DO TO GET EFFECT IN E-RETURN?