element.onmouseleave = handlerFunction; var handlerFunction = element.onmouseleave;
handlerFunction should be either
See the DOM event handlers page for information on working with
mouseleave event is fired when a pointing device (usually a mouse) is moved off the element that has the listener attached.
mouseleave event documentation for more information about the event.
|WHATWG HTML Living Standard
The definition of 'mouseleave' in that specification.