coupon field not showing up on subscription forms

I have updated just earlier to the new membership update. I did this for the coupon feature.
I can now create coupons/discounts on the back end but there is no field appearing on the user end on the subscription form before user is taken to the payment gateway.
Do I need to enable something? or do something to the code to make a coupon field appear in the create an account form with membership?
Please help!??