data in portal

[pacosokal]

Hi - I'm new to the forum and have been using FMPro for 5 years in my business.
I have a DB for invoicing. I have items in multiple sizes at different price points.
In my inventory file I've made a portal that displays the corresponding price (from the related 'prices' file). The inventory file also has a field that displays the quantity.
I want to have a field that calculates the total resulting from multiplying the value in the 'quantity' field in the inventory file by the value displayed in the portal from the 'prices' file which can then be summarized.
The problem I'm having is that the portal displays the correct value but my calculations always default to using the first value listed in the prices file.
The prices file may have 4 different sizes with each size having a set price. By basing the relationship on the sizes, I'm able to display the correct price in the portal in the inventory file, but unable to make a calculation based on the value in the portal.
I imagine a solution that would copy the value in the portal into a new field in the inventory file that could then be used in the calculation, but don't know how to do it.
Thanks for any help you may offer.

 

[pacosokal]

paco again - well ... I spoke too soon. My portal is finding prices, but it is not finding the correct prices.
So... back to the beginning.
I am working with FileMaker Pro 6.0.
I have a prices file that contains a unique name field a size field and a price field among others. Each unique name may have multiple sizes and prices.
For example:
record 1: anthemis tinctoria, 1inch, $1.00
record 2: anthemis tinctoria, 2inch, $1.50
An inventory file has a unique name field and a quantity field and a size field and a location field, among others.
For example:
record 1: anthemis tinctoria, 10, 1inch, 6
record 2: anthemis tinctoria, 20, 1inch, 13
record 3: anthemis tinctoria,10, 2inch, 7
I need to determine the total value (price) of all the records in the inventory file.
This is part of a larger DB and the unique names have been how I've related files in the past.
Sorry for the false start, your help is most appreciated - paco