This element defines an event handler on a binding that reacts to a mouse movement or keyboard press on the binding. Some executed code is contained in the handler. This code can go directly under the element or in the action attribute.
The attachto attribute determines where the event is received -- in the element, document, or window. The default receiver is the bound element. The phase attribute has three possible values -- capturing, bubbling, and target -- that determine which part of the event flow and default is bubbling
The button, charcode, keycode, and modifiers attributes act as filters. For example, the value of button must match the label of the button that triggers the event.
The section "Event Attributes," later in this chapter, contains a complete list of events.