When creating calculations and scripts, you must associate each entry with a specific form event. Each form event represents a change in the form’s state that initiates at a specific time. The change in form state can occur during form rendering on the server by LiveCycle Forms ES, or on the client by Acrobat or Adobe Reader while a user is filling a form. When a change in the state of the form occurs, any calculations or scripts associated with the event are processed automatically.The event you use when creating a calculation or script will, to some extent, determine what you must include in your calculation or script. For example, the amount and type of information available on a form may be different depending on the event timing you choose; therefore, a calculation or script that retrieves a value from a field may have different results if run before instead of after a form filler performs certain actions. For more information about events, see “Events”.Depending on the type of form you are creating, some events may never occur. For example, if you are creating a form that has a fixed layout and no interactive objects, then interactive events associated with form filler actions may never occur and, as a result, any scripts associated with those events will not run.Although LiveCycle Designer ES includes support for a wide variety of form events, it is possible to accomplish a wide variety of common calculation and scripting tasks by using only a few events that occur at major changes in a form’s state, such as the following events: