The program utilities and setup window contains a 'Program Setup'. Tab. Select that tab and you'll see the option where you can enable or disable the automatic purchase order numbering.

Notes for new users:
This option will be enabled by default. When you place purchase orders the numering will begin from "00001" but you can change that by typing over the number when you place your first order.

Notes for users upgrading from a previous version of miniMrp.
If you've already used miniMrp to place purchase orders then Auto-Numbering will be switched off unless you enable it via the option shown above. When you switch Auto-Number on then miniMrp will scan your existing purchase orders to see if a numerical 'pattern' exists and, if possible, allocate the next free purchase order number the next time you place an order. If no pattern exists, IE if all your order numbers contain letters or punctuation then numbering will begin at '00001' but you can change that by typing over the suggested number when you place your first order.

Notes for all users:
When AutoNumbering is enabled you will still be permitted to manually enter a purchase order number overwriting the one suggested by miniMrp. However, remember that any number you enter manually will affect the auto-numbering sequence. If you lose the sequence and have forgotten your last order number then return to the setup window shown above and disable and then re-enable the autonumbering option which prompts the software to scan your orders and allocate the next free number.

When auto numbering is enabled the field where you enter Purchase Order numbers will only accept numerical values 0 - to - 9.

When auto numbering is disabled then the Purchase Order will accept all alpha-numeric values.