Adding promotions and happy hour as discount and print in bill

Hi,

Please add promotion and happy hour as discount (total savings) and print it in the bill.

EX:- 1) If we setup product that cost 1000 discounted 10% print 100 as total savings in the bill.

         2) If we setup product that cost 1000 fixed price 900 print 100 as total savings in the bill.

Thanks team.