This article makes a detailed study of how to write Keystroke and Format scripts. Several custom scripts are presented, including one that processes U.K. postcodes. A extensive listing of the built-in functions is made, and numerous examples are presented. We discuss mostly the text field, but there are sections devoted to the the combo box (which has the same tab structure as the text field), and we finish up with the Selection Change tab of the list box. Selection Change script is implemented in the same way as a Keystroke script.