Bats & browser events
Try a local event handler, then consider which objects a widget callback should receive.
Bats was one of the sample links on the historic ADsafe site. This page preserves that landing path. The new demonstration below illustrates local event handling; it does not reproduce the archived game or run the historical ADsafe runtime.
Bats counted: 0
Events are part of the interface
In ADsafe's document model, event handlers operate through the wrapper supplied to a widget. An event interface deserves the same scrutiny as a DOM update method: which objects does a callback receive, and what can it reach through them?
Explore the DOM API for the relationship between selections, wrappers and events.