Ok Still Can not figure it out..
I am in Invoice view. I created a proposal which is a different Form View from Invoice. So its all in the same DB. i have the relationships right etc.
I have a field, that is a drop down.. called Proposal ID. i want to be in Invoice view, "Creating a new invoice" and choose the Proposal. This will copy all Line Items from Proposal xyz into my new invoice. whats a good way to get this done?