Adds a listener to an event type.
The type of event to listen to.
The function that gets called when the event is fired.
Fire an event type.
Checks if listener is added to an event type.
The type of event to listen to.
The function that gets called when the event is fired.
Removes a listener from an event type.
The type of the listener that gets removed.
The listener function that gets removed.
JavaScript events for custom objects
Example
See