I'm trying to create a second invoice template and add another print invoice link so I can print a standard invoice but also print a 'internal' invoice copy with an 'Official Use' table in which can be filled out by staff on the print out.
I've found the template invoice.tpl and print_invoice.tpl in /basic/mail/orders/
created two new files called invoice.dirty.tpl and print_invoice_dirty.tpl and pasted the content of the original files in the new ones, changed the path and added the table I wanted.
I've managed to locate the code for the 'Print Invoice' link and duplicated that changing the href by adding _dirty to the original 'orders.print_invoice?' but when I try the link it opens the popup ok but I get a 404 error, i've checked the permissions and changed them to full but still it won't play ball...
it seemed quite simple and I expected it to work but obviously i'm missing something, any guidance would be appreciated.