Autopopulate related fields

Autopopulate related fields

I have 2 forms:
1. Salons - with the fields "Name" and "Area"
2. Sales - with the fields "Date", "Name" and "Area"

The "Name" field in the Sales form is a lookup from Salons. I need a script that will autopopulate the "Area" field in the Sales form, with the related area from the Salons report, whenever someone selects the "Name" field in the Sales form.