今天有一个项目上线测试，发现很多页面在IE下报错，出错的意思大概都是“null为空或不是对像”，使用IE的调试工具调试了一下，出错的位置为：


原因应该是document.getElementById("")获取不到内容，由于大部分页面都使用<object/>标签嵌入了一个Flash，而且<object/>标签内没有id属性，于是在<object/>标签里添加一个id，问题解决了。

对于在页面里嵌入Flash，更常见的做法是使用SWFObject，转一篇SWFObject的官方文档（http://code.google.com/p/swfobject/wiki/documentation），中文。

What is SWFObject?

SWFObject 2:

• Offers two optimized Flash Player embed methods; a markup based approach and a method that relies on JavaScript
• Offers a JavaScript API that aims to provide a complete tool set for embedding SWF files and retrieving Flash Player related information
• Utilizes only one small JavaScript file (10Kb / GZIPed: 3.9Kb)
• Is the successor of SWFObject 1.5, UFO and the Adobe Flash Player Detection Kit
• Intends to unify all existing Flash Player embed methods and provide a new standard for embedding Adobe Flash Player content

Why should you use SWFObject?

SWFObject 2:

• Is more optimized and flexible than any other Flash Player embed method around
• Offers one solution for everybody: It shouldn't matter if you are an HTML, Flash, or JavaScript developer, there should be something in it for everyone
• Breaks the cycle of being locked into vendor specific markup and promotes the use of web standards and alternative content
• Uses unobtrusive JavaScript and JavaScript best practices
• Is easy to use

The A List Apart article Flash Embedding Cage Match describes the full rationale behind SWFObject 2.

Why does SWFObject use JavaScript?

SWFObject 2 primarily uses JavaScript to overcome issues that cannot be solved by markup alone; it:

• Detects the Flash Player version and determines whether Flash content or alternative content should be shown, to avoid that outdated Flash plug-ins break Flash content
• Offers functionality to revert to alternative content in case of an outdated plug-in by means of a DOM manipulation (Note: if no Flash plug-in is installed the HTML object element automatically falls back to its nested alternative content)
• Offers the option to use Adobe Express Install to download the latest Flash Player
• Offers a JavaScript API to perform common Flash Player and Flash content related tasks

Should I use the static or dynamic publishing method?

SWFObject 2 offers two distinct methods to embed Flash Player content:

1. The static publishing method embeds both Flash content and alternative content using standards compliant markup, and uses JavaScript to resolve the issues that markup alone cannot solve
2. The dynamic publishing method is based on marked up alternative content and uses JavaScript to replace this content with Flash content if the minimal Flash Player version is installed and enough JavaScript support is available (similar like previous versions of SWFObject and UFO)

The advantages of the static publishing method are:

1. The actual authoring of standards compliant markup is promoted
2. Best embed performance
3. The mechanism of embedding Flash content does not rely on a scripting language, so your Flash content can reach a significant bigger audience:
• If you have the Flash plug-in installed, but have JavaScript disabled or a use a browser that doesn't support JavaScript, you will still be able to see your Flash content
• Flash will now also run on a device like Sony PSP, which has very poor JavaScript support
• Automated tools like RSS readers are able to pick up Flash content

The advantages of the dynamic publishing method are:

1. It integrates very well with scripted applications and enables the use of dynamic variables (flashvars)
2. It avoids click-to-activate mechanisms to activate active content in Internet Explorer 6/7 and Opera 9+. Please note that Microsoft has phased out most active content from its Internet Explorer browsers