Basic Demo

Box #1

Box #2

Box #3

Box #4

Box #5

Hover me!

Box #6

Box #7

Box #8

Box #9

Move your mouse cursor over Box #5 and see how anything else on this page becomes dimmed.

This is the complete Javascript source code: 

            $(function() {
                $('#actionBox')
                .mouseenter(function() {
                    $(this).dimBackground();
                })
                .mouseleave(function() {
                    $(this).undim();        // Note: We could also use `$.undim();`
                });
            });