I don't see any attached relationships, only a screen shot of your layout.
Most order or invoice systems start with these basic relationships for invoicing a sale:
Do you have this basic structure?
I attach another screenshot.
Yes, I have the basic relationship but it is "extended" it to deal with the packing.
I see two option that should work:
Display a portal to Shipping_Lines and add buttons in the portal that use the data in Shipping_Lines to create records in Packing Lines. This would allow you to click a row for a book or group of books in the portal and the script adds a portal rwo in Packing Lines with the same _kf_book_# and quantity. (You need to add this field to Packing_lines so that you can identify the books in the Packing_Lines portal. Once you've clicked such a row to create a new row in Packing_Lines, you can edit the Quantity if only a portion of the quantity will be packed in that specific box.
You can enhance this interface design by adding a "packed" field in Shipping_Lines and a portal field that filters out portal rows when a row is designated as "packed".
A conditional value list of book#'s can be defined that lists only the books listed in Shipping_Lines for a given Shipping record. The trick here would be to set up the conditional value list to "dwindle"--dropping out books that have been already packed.
Thanks for reply.
I have no knowledge (yet) to apply option #1.
Option #2 is easier and is the one I tried to apply. The problem is cannot find the correct combination/setting for the value list!
Actually I do not need the list to drop the books already packed because I will create some calculation fields to cross check the quantity of packed books with the total quantity in the shipping form.
Option #2 is easier
I suggest that #1 is actually easier to set up here. I would also suggest that it gives you a more complete picture at a glance of what you are packing in the shipping boxes.
Can you add a portal to shipping lines to your Packing layout? You should be able to just use the portal tool to draw a box on your layout and then select Shipping Lines from Show Related Records From.
Then a button with a very short script can be added so that clicking the button adds an entry for that book in the PackingLines portal.