Regrading draft and document in Purchase order

Hi Experts,

   After the document draft is created and approval. The draft is approved  i need to remain in the purchase order list but not showing .

How to make this . For eg : PO 419 is created as draft not able to see in the purchase order list. if i need i am able to see through document draft report. But customer wants to show in the same purchase order list. How can i do this.

Please suggest me