I am new to openERP. I am customizing PO module. I want PO implementation in this way: once PO is confirmed by Admin, then user and manager can see the PO. They should not be able to Edit, Delete. Only Admin can perform those operations.

If we give Access rights in 'Purchase Order' model object, it will affect to all POs. I just want to do for Confirmed POs only.

Any suggestion will be greatly helpful for me.