SD scheduling agreement in MD04

Hi all

I have this problem: a customer manage sales scheduling agreement, for example item of 500 pieces

in MD04 i see -500

then the customer creates order from scheduling agreement. now in MD04 i see both

- 500 from scheduling agreement

- 500 form sale order

why??? I need that when the sale order from scheduling agreement is created, the row inMD04 referred to that item disappear.

how can obtain it?

regards