浏览器兼容性

<!--[if lt IE 9]>
 <script type="text/javascript" src="js/html5shiv.js"></script>
<![endif]-->
 html5shiv.js下载地址
https://github.com/aFarkas/html5shiv/releases

Every browser comes with a different set of internal, basic CSS styles.

Every browser will render a page differently even if it lacks any CSS styling of there own.

To avoid having any side effects you can use a so called CSS reset style sheet in your page
to make sure that every browsers starts rendering with the same basic set of rules.

A few commonly used reset style sheets are:

Normalize.css
HTML5Reset
Eric Meyers CSS Reset

Make sure to have one of these added as the first style sheet to your page to ensure a proper CSS reset.
Of course many popular front-end frameworks like Twitter Bootstrapped already include a CSS reset
so there is no need to add a second one.

问题症状：几个img标签放在一起的时候，有些浏览器会有默认的间距，
加上通配符也不起作用。

碰到几率：20%

解决方案：使用float属性为img布局

备注：因img标签是行内属性标签，所以只要不超出容器宽度，img标签都会排在一行里，
但是部分浏览器的img标签之间会有个间距。去掉这个间距使用float是王道 。

IE8：filter：alpha（opacity=value）；（取值范围1--100）

其他：opacity：value；（取值范围0--1）

标准的事件绑定方法函数为 addEventListener，但 IE8 以下是attachEvent；

event.x & event.pageX

一般浏览器是 XMLHttpRequest，IE5* 是activeXObject
(IE5* 可以不考虑了，不过这点用来应付面试可以表示下是了解过的？)