如果您确实需要执行此操作，那么我建议您使用jquery来实现您想要的操作.

查看这些文章.

前两个用于进度条，但概念相同.
在使用JQuery和CSS进行任何任务或进行中的过程中显示进度栏(加载框) [ ^ ]

使用jQuery显示进度栏 [五个不同方式进行jQuery AJAX调用的工作示例 [使用JQuery的页面加载效果

当然，我不能忘记
JQuery.com

If you really need to do this, then I would suggest using jquery to achieve what you want to do.

Check out these articles.

These first two are for progress bars, but the concept is the same.
Displaying a Progress Bar (Loading Box) During any Task or Work in Progress using JQuery and CSS[^]

Showing Progress Bar Using jQuery[^]

More general jquery knowledge.
A Working Example of Five Different Ways to Make jQuery AJAX Calls[^]

Offsite article
Page Loading Effects with JQuery

Of course, I can''t leave out
JQuery.com