Roll Overs
This is probably the most common visual effect on the web. A Roll Over is anytime an image (such as a button or a link) changes when you put your mouse cursor over it. You may not realize it but this simple visual effect provides two important Web design elements; Interactivity and Visual Feedback.

Navigation
Easy and intuitive navigation is the fundamental backbone of any good Web. We can use Javascript to create dynamic menus that are very easy to use and provide quick navigation to many parts of website.

Slide shows
Another popular application of Javascript is to display images on the screen. Slide show displays can be sequenced or random and they can play automatically or only when prompted.

Email Obfuscation
It's important to have contact information on your website, including your email address. Javascript provides the ability to hide your email address from spammers while allowing the public to contact you normally.