You use the Behaviors panel to attach behaviors to page elements (more specifically to tags) and to modify parameters of previously attached behaviors. For background information about what behaviors are and how they work, see Using JavaScript Behaviors. For information on how to attach a behavior to an event, see Applying a behavior.
Behaviors that have already been attached to the currently selected page element appear in the behavior list (the main area of the panel), listed alphabetically by event. If there are several actions for the same event, the actions will execute in the order in which they appear on the list. If no behaviors appear in the behavior list, then no behaviors have been attached to the currently selected element.