accounting for Coupons

[mindgaap]

I am hoping to find some assistance in resolving an accounting issue relating to Coupon redemption and the related accounting entries. The background is as follows. My company is a retail company. We issue store coupons to customers that make them eligible for discounts on certain purchases. The effect, of course, is a reduction in the sales price. Once a coupon is redeemed, we send the coupon to our supplier (vendor) for the specific good. Our supplier then sends us a credit memo (note) in an amount close to the discount amount.
Does anyone know what the accounting entries would be for the coupon redemption and the subsequent reimbursement from the supplier?
Our company is located in the EU region (Scandinavia) to be specific but even GAAP treatment guidelines are welcome.

Thanks in Advance