Do not allow a user to upload an invoice to a PO if it will over-invoice the PO
Could you please ensure that the system enforces rules to prevent over-invoicing against purchase orders? For example, if a purchase order has a value of 100 and an invoice for 50 is already uploaded, the system should not allow users to upload another invoice for 60, as this would exceed the PO value. Additionally, if a purchase order is already fully invoiced, users should be restricted from uploading any further invoices. These measures will help maintain accurate invoicing and prevent overcharging.