"I do not want to rely on our employees to manually check that an existing customers information is correct. If that customer information screen pops up automatically, that will solve that issue."
I can interpret your post more than one way.
How does your invoice function currently?
What events precede ::Customer_Name_Final displaying a value?
Does the user find or select a customer from an existing list or table?
The user enters (usually) the customers last name. When they hit 'Enter' FM searches for matches. If it finds just one then it populates the (in my particular case) field called customer_invoice_ref::Customer_Name_Final.
As soon as that field gets a value, I would like the 'Edit Customer' screen to appear with all of that particular customers information showing.
Does that help?
Sounds like you have a script trigger set on the last name field. You should be able to find this script and modify it to do what you want. I have no way to tell exactly how the script was written, but it's very likely that it's performing a find on the "edit customer" layout. If so, you may need to do no more than add a go to layout script step to bring up this screen. If this screen normally pops up in it's own window, you may also need to add code to do this in a new window.