Home > Reference > Script steps reference > Fields script steps > Set Field By Name
http://www.filemaker.com/help/html/scripts_ref1.36.40.htmlExample 2The following example replaces the contents of the Country field located in Table1 with the data located in the Name field in related Table2.Note To ensure proper evaluation, FileMaker Pro must treat the target field as a literal string. Therefore, you must include quotation marks around the calculated target field.
Set Field by Name Exposed
You might want to put estimate and invoice data in the same tables. A field in the main table can identify which record is an invoice and which an estimate. Then, from a "business needs" point of view, you can decide whether to create an invoice from an estimate by changing the value in this field or by duplicating it. This can simplify your relationship graph and reduce the number of tables needed in your database and also makes it much easier to use estimate data to produce an invoice.