Everything you need to know about viewing, editing, and closing Purchase Orders.
In order to manage your Purchase Orders (P/Os), you will need to, on the left-hand menu bar, click Purchasing > P/O Management.
This will bring you to the P/O list screen. Here, you can search by P/O # (or Channel Order ID, Vendor #, etc.), add a new P/O, or view all existing P/Os by clicking Apply.
Once you click Apply (or search by specific P/O #) and see them appear, you can click on the P/O number to get to the Purchase Order Management screen. Here, you can View, Add, Edit, Delete, Cancel, or Close P/Os.
Viewing and Editing P/Os
Make sure you are in Edit Mode if you want to make any updates to the P/O. Best practice is to not make edits after the P/O has been sent to the warehouse to be received, although you can if you need to. 
You can also generate a Proforma Invoice here when dealing with an existing P/O. To do so, in the General section, just click Show More.
Next, click “Create Proforma Invoice."
This will generate a clickable Proforma Invoice Number. Clicking on it will open the A/P Proforma Invoice Management screen (see related article).
Printing P/Os is very simple. You will just click Reports > Print Report.
Tip: You can also print P/Os from the list screen by selecting the P/O(s) you'd like to print, then clicking Action > Print Selected.
It's possible to create an A/P Deposit from a P/O as well. Check out this user guide and scroll to P/O Deposit - Via an existing P/O.
You can also use the Activity tab to see all related records to this P/O (P/O Receives, A/P Bills, etc.). This tab will show you the Type of record as well as any related dollar Amount.
Closing P/Os
Before closing a P/O, all related Purchase Order Receives must be completed and closed. Once that's done, from the Purchase Order Management screen, change your Process Mode to Close.
A new Close button will appear. Click it.
Click Yes.
If you need to make edits to or re-open a closed P/O, you can do so for certain fields (not related to the quantity of items received). From the P/O Management screen, make sure you are in Edit mode. Make whatever changes you need to then hit Save.
Warning: Don't forget to re-close the P/O when it's time!
For more information on Purchase Orders, check out How do I create a Purchase Order?