lock "closed" records to prevent data modification
I have Sales Order system. One the SO layout, I can edit and save all of the Sales Order records without any issue now. But, I need to lock record, if the Sales Order record is closed. FYI, I have one status field for each Sales Order record. It is "Open" when it is created. And it will be changed to "Closed" by script when the Sales Order is shipped. I need to lock all of the fields on the layout or change the record to read only, if user select any "closed" record for reviewing. By the way, on the SO layout, I have Sales Order Line portal. I need to lock the portal records also.