Every calculation or script you attach to a form object is associated with a specific event. An event is defined as a particular occurrence or action that can change the state of a form and, when the change of state occurs, automatically invoke a calculation or script associated with the event. Events occur at various times, from the beginning of the form rendering process when merging data with a form design, all the way through to a form filler interacting with objects on a form in a client application. By applying calculations and scripts to specific events, you can control every aspect of how you present form objects, as well as form data, and how the objects and data respond to form filler interaction.