Data from Lookup field doesn't show
I am very new to Filemaker and am trying to make a 'basic' database for my fitness studio which includes Clients and their Memberships. I have made 4 tables ; Clients, Invoice, Line Items and Products and made relationships between them the best I understand. In the layout related to the Invoice table I have made a portal following instructions about making 'Conditional Relationships' so that when I make a new record I click in the first field (Category) which gives me a drop down menu of the categories for membership. When I select a type of membership (ie Group Classes) the next field automatically gives me a drop down menu of the types of Group Class memberships available (ProductName). The Category and ProductName have been set up as records in the Products table and each has a unique ID. This seems to work fine. The next field is an Amount and the next one after that is the Price which is a Lookup value from the Product table.
It is driving me insane to try and get the Lookup value (Price) to show in the field. I have purchased the Missing Manual via Kindle to try and find out and also checked out this forum where a helpful response (http://fmforums.com/forum/topic/63425-auto-fill-one-field-with-text-from-two-fields/#entry300150) allowed me to download a sample file (InvoiceDemo) but to no avail !
Any help would be greatly appreciated - I have uploaded a 'screencast' at http://screencast.com/t/PWaO3CEZK showing the steps and layout of the database. Anyone who can give me some of their valuable time and knowledge please also note that I am a complete beginner so you will have to keep things simple for me.
Would really appreciate any help - best regards - Richard