Create a Invoice from a order

1. Go to the header Orders
2. Open the order that you want to invoice
3. On the top header press Create invoice
4. On the invoice order pop out set, 
   1. Target date - To what date the invoice should charge for, this will dictate what unprocessed usage should be invoiced for
   2. Invoice date- The actual date on the invoice when it is issued
5. Press Create invoice button
6. Once the invoice is created it needs to be Posted. Once a invoice is posted it can no longer be deleted but must be created.