特殊事件委托

delegating.js

/* http://www.quirksmode.org/blog/archives/2008/04/delegating_the.html */


<ol id="dropdown">
	<li><a href="#">List item 1</a>
		<ol>
			<li><a href="#">List item 1.1</a></li>
			<li><a href="#">List item 1.2</a></li>
			<li><a href="#">List item 1.3</a></li>
		</ol>
	</li>
	[etc.]
</ol>

$('dropdown').onmouseover = handleMouseOver;
$('dropdown').onmouseout = handleMouseOut;
$('dropdown').onfocusin = handleMouseOver;
$('dropdown').onfocusout = handleMouseOut;
$('dropdown').addEventListener('focus',handleMouseOver,true);
$('dropdown').addEventListener('blur',handleMouseOut,true);