sales order user exit name to set the rejection reason code
I have a requirement where I need to set automatically via user exit code a particular reason for rejection code based on some conditions while creating the sales order. I need to know the name of the sales order user exit that will solve this problem. I have looked at these following user exits:MV45AFZZ and MV45AFZB and I am not sure which one to use.
I would appreciate if some one can guide me exactly which form to use as you know these user exits contains many forms.
Any help would be greatly appreciated.