And How is your database currently designed? What tables and relationships do you have. What version of FileMaker are you using? Are you adapting the Invoices Starter Solution File? Adapting the Product Catalog File? Both? or ???
One of the fields on the invoice layout is the purchaser's name (which comes from my product details page),
That doesn't really make sense to me. Why would the purchaser's name come from a product details page? By "page" do you mean "layout"?
Data isn't stored in a layout, it's stored in a field of a table. A layout is then the means we have to see and modify the data in that field.
I'm using the Product Catalogue file. I've kept those table and relationships.
I'm using Filemaker Pro 12.
My purchaser's name comes from a drop down menu with 4 different company names as values. At the moment, I am using this field on my product details layout and also on my invoice layout. The value is selected on the product details layout. When I switch to my invoice layout I would like to find a way for the selected value within this field to automatically generate the address for this company name.
Does that clarify?
And what changes have you made to that starter solution?
There isn't any invoice table in that starter solution so I am guessing that you've added some more tables and relationships to this starter solution. I'll need to know what changes have been made.
Since a given product might be purchased by any number of different people, I don't see why you would put a purchaser field in the product table. I could see putting a supplier or vendor field in the product table that you would use to identify who you acquire the product from for resale, but putting a field for the purchaser in the product table and on the product details layout still has me puzzled.
I would recommend that you examine how the Invoices starter solution is set up and then recreate those tables and relationships in the Product Catalog file such that the Products table in the Product catalog table can link to these added tables for customers, invoice and invoice data (lineitems) the way that the product table in Invoices links to them.