Unique invoice number

[Former Community Member]

Hi



I have made a invoice as a pdf in Adobe Designer 7.0. The invoice contains some fields for date, costumor information, and so on.



The invoice also contains an invoice number, and the question is:



How is it possible to make an invoice number, which increases by one, every time a new invoice is made?



P.S. I have only a very little experience in scipting.



Hope you can help