The Sales & Receivables Setup Table
Place a check mark in this field if you want the program to automatically calculate the invoice discount amount in connection with sales documents.
The invoice discount amount will be calculated automatically if there is a check mark in this field and you do one of the following on a sales document:
Click the button that has the name of the particular document type, for example Invoice, and then click Statistics
Click Posting, Test Report
Click Print
Post the document