Microsoft Access 2016 - Invoice Help!!

[joe904]

Hi Guys,
I am creating an invoice using MS Access for a friend, but I am having some difficulty finishing it. I created a table called "Customers" and "Invoice Details." Invoice Details has all of the invoice info such as Invoice Number, TotalHours worked, and UnitPrice. The problem that I am having is that I created a form called "Customer Input". It has tabs one for "General" where the customer data is input, and another for "Invoice layout" where they can enter each separate line of the invoice. When I set up the tabs for the form, I had to select a "Record Source" which I set up for the customer data. Since the other tab pulls info from the "Invoice Details" table, how do I connect this record source. I have tried this expression, but it does not work:
[Invoice Details]![TotalHours].
Hopefully I have explained this correctly and have made some sense. If there is a better way of setting this up, I am welcome to any and all suggestions. I have included a picture to help explain.

 

[USAFRet]

Create a Query that grabs the data you need. The query can take data from multiple tables.
Use that as the Record Source.