Web application "Ajaxian." Therefore, the best way to look at Ajax is as a programming pattern to build the next generation of Web applications that bring us closer to what end users know from their client-server desktop clients. It is important to note that Ajax is not bound or related to J2EE and Java; rather, it can be used with .NET, PHP, CGI, and Perl as well. The good news about Ajax is that it doesn't require an example more complex than "hello world" to explain its principles. This how-to provides you with a first-class, hands-on experience for building an Ajax type of application in J2EE with Oracle JDeveloper. The technologies used within the exercises are: JavaScript - The JavaScript language executes on the browser client and is in the core of Ajax. You use JavaScript to perform logical, mathematical and functional operations on the client side. Using The Document Object Model (DOM), JavaScript can be used to dynamically manipulate a Web page displayed in the browser. Document Object Model (DOM) - A virtual tree representation of a HTML page document that is kept in the browser memory where it can be accessed using JavaScript. The DOM tree can be used to dynamically manipulate UI components of the current HTML page in the browser. XmlHttpRequest - The XmlHttpRequest object is a browser-side API to access a remote server and is available in almost all of modern browsers. The XmlHttpRequest object enables a client to fetch new data from a remote