Calculating form fields

You can perform mathematical calculations on two or more existing numeric field entries and display the results. You perform calculations within text or combo box fields. You can apply predefined operations, or you can create custom operations using the JavaScript programming language.

In the first part of this section, you'll create a Total field that adds values from the Airfare, Fares, Personal Auto, and Rental Auto fields in the Transportation section of the form. Then you'll set a custom calculation for the Personal Auto field.