Can you trigger a script to open Customer Inquiry when clicking on Totals tab in SO Invoice Data Entry?

SOLVED

I am not well versed in scripting, but I know it can do a lot of wonderful things.  I'm hoping this will be possible.

I have a customer that creates credit memos but they do not always apply them.  They would like a way to checking their customer's invoices at the time they are doing invoices.

I was thinking there might be a way of triggering the Customer Inquiry screen (opened to the Invoices tab for the customer being invoiced) when you go to the Totals tab in SO Invoice Data entry, sort of the way it works when you click on the Customer button from Invoice Data entry.

If it can't be done when going to the totals tab, maybe I can create a button that would trigger it?
Is it possible?