Element.Events.change.js

/*<ltIE9>*/
if (!window.addEventListener) (function(){

var update = function(event){
	event.target.store('$change', event.target.checked);
};

Element.Events.change = {
	base: 'click',
	condition: function(event){
		var target = event.target;
		if (target.type != 'radio') return true;
		return (event.type == 'keyup') ? !target.checked : target.checked;
	},
	onAdd: function(fn){
		if (this.type == 'checkbox' || this.type == 'radio') this.addEvents(this.retrieve('$change:events', {
			focus: update,
			keydown: update,
			keyup: function(event){
				var code = event.which || event.keyCode,
					element = event.target,
					value = element.retrieve('$change');
				if (value != null && value != element.checked && (type == 'checkbox' && code == 32) || (type == 'radio' && code >= 37 && code <= 39)) fn.call(this, event)
			}
		});
	},
	onRemove: function(){
		this.removeEvents(this.retrieve('$change:events')).eliminate('$change:events');
	}
};

})();
/*</ltIE9>*/