Feature Request: Notify/lock a SO or PO when multiple Users watching

Hi Team,

It would be good to know/notify/lock a SO or PO when there are multiple staff trying to open the same one. We had two users connected to the same PO making different changes. 

The request is that if one user has a SO/PO open, then anyone trying to open the same SO/PO can view as read only (with information current at the time of opening SO/PO). The system should also notify the second user that another user currently has the SO/PO open.

Thank you.