Javascript web page black/white effect implementation code (compatible with IE/FF, etc.) _ javascript skills

Today, I saw a good method recommended by someone on the Internet. After a try, the effect is still acceptable. You can customize a part of the webpage to become a gray color (black and white ). The demo address below is partial gray

Partial gray demo address: http://demo.jb51.net/js/grayscale/index.html
Full gray demo address: http://demo.jb51.net/js/grayscale/demo2.htm
Usage:

1. first introduce the grayscale. js file to the webpage.
2. Execute the grayscale function.

Sample Code:

The Code is as follows:

Grayscale (document. body); // the entire site turns gray
Grayscale (document. getElementById ("main"); // The specified element is dimmed.
Grayscale. reset (document. getElementById ("main"); // restore a specified Element

Package