jQuery Tooltip
jQuery Tooltip 插件取代了原生的工具提示框，让它们可自定义，您只需要调整它们的内容、位置和外观即可。
该插件目前版本是 1.3，已经很长时间没有更新，推荐使用 jQuery UI 工具提示框（Tooltip）。
如需了解更多有关 jQuery UI 工具提示框（Tooltip）的细节，请查看 API 文档 jQuery UI 工具提示框部件（Tooltip Widget）。
实例演示
jQuery Tooltip 插件演示。
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>jQuery UI Tooltip - Default functionality</title>
<link rel="stylesheet" href="//code.jquery.com/ui/1.11.4/themes/smoothness/jquery-ui.css">
<script src="//code.jquery.com/jquery-1.10.2.js"></script>
<script src="//code.jquery.com/ui/1.11.4/jquery-ui.js"></script>
<link rel="stylesheet" href="/resources/demos/style.css">
<script>
$(function() {
$( document ).tooltip();
});
</script>
<style>
label {
display: inline-block;
width: 5em;
}
</style>
</head>
<body>
<p><a href="#" title="That's what this widget is">Tooltips</a> can be attached to any element. When you hover
the element with your mouse, the title attribute is displayed in a little box next to the element, just like a native tooltip.</p>
<p>But as it's not a native tooltip, it can be styled. Any themes built with
<a href="http://jqueryui.com/themeroller/" title="ThemeRoller: jQuery UI's theme builder application">ThemeRoller</a>
will also style tooltips accordingly.</p>
<p>Tooltips are also useful for form elements, to show some additional information in the context of each field.</p>
<p><label for="age">Your age:</label><input id="age" title="We ask for your age only for statistical purposes."></p>
<p>Hover the field to see the tooltip.</p>
</body>
</html>