i have a typical invoice and orders scenario. i have a view module which is just a datagrid which lists the invoices and a hyperlink button for the editURL which then opens the edit module which gives the users the ability to edit the details of the invoice, but i want to give the user the ability to add items to the order.

Am i best to just add a grid to my edit module and let them add orders to the invoice or am i able to have a 2nd module just for adding items. I have created multiple definitions but was unsure on how to use the typlical editURL but then have it open more than 1 module.

Any assistance on how other have achieved this would be great, thanks.