billing document to FI posting - negative posting on credit.

Hi all..

I have the following situation :

Sales order with a discount condition. After the billing the system generates the accounting note:

ZRO1 1 01 11 client 847,88 EUR A1

ZRO1 2 50 70100000 RevFrFinishProdSales 400,00- EUR A1

ZRO1 3 40 70100000 RevFrFinishProdSales 20,00 EUR A1

ZRO1 4 50 44270000 VAT collected 135,38- EUR A1

ZRO1 5 50 70100000 RevFrFinishProdSales 350,00- EUR A1

ZRO1 6 40 70100000 RevFrFinishProdSales 17,50 EUR A1

Account 701 is a credit account ; so for the discount positions (3 and 5) it should be

ZRO1 3 50 70100000 RevFrFinishProdSales 20,00- EUR A1

where can i chanhe this type of posting?

10x.