We have a returned product which we processed a credit memo. The product has returned back to inventory. When we go to close the sales order under SO-A and hit the delete button it states "At least one invoice has been created and posted from this sales order. Do you want to delete the entire sales order anyway?"  Not sure if I should proceed with deleting the sales order. The concern is that when you look at SO-A it shows a dollar amount showing beside the sales order #.  
 
Please advise whether it is ok to go forward and close the sales order or not. If we need to zero out the sales order please advise what the best way to do this is.  
 
Thank you.

Thanks Lynn.