how can we add our own date field in purchase register?

sir,
if we add one field in pur reg for a date then it is not activated for entering date. why?
purpose is to add one user date and store in voucher object for further reporting.
for eg , user want to add bill send for checking date as well as bill received date mannually in purchase register. i try but its not working.

pl help

 

I think you should use Audit Features in Tally. It will be easier for you.