How to show client-ID and order-nr in invoice?

The invoice, which is generated after a successful transaction, contains the invoice-ID.
Besides this invoice-ID I also want to show Client-ID and order-nr on the invoice.
Is there any way to manage this?

Hi,

The solution would be to directly edit your "invoice" file of your "order" view of your current back-end template and to add the code which will display your "client id" and "order-nr".

Hope this will help you a little.