Unobtrusive JavaScript

Unobtrusive JavaScript is a general approach to the use of JavaScript in web pages. Though the term is not formally defined, its basic principles are generally understood to include:

• Separation of functionality (the "behavior layer") from a Web page's structure/content and presentation
• Best practices to avoid the problems of traditional JavaScript programming (such as browser inconsistencies and lack of scalability)
• Progressive enhancement to support user agents that may not support advanced JavaScript functionality