the acronym for Asynchronous JavaScript and XML

 a DOM* that is accessed with JavaScript to dynamically display, and to allow the user to interact with the information presented * DOM – document object model

 DOM (document object model) is a strategic and open effort to specify how to provide programming control over documents.

Source: w3schools.com/ajax

 Classic (static) web pages, (which do not use AJAX) must reload the entire page if the content should change.  Examples of applications using AJAX: Google Maps, Gmail, Youtube, and Facebook tabs.

Render Logo Render Section 1 Download File (Part 1) Download File (Part 2) Render Section 2 from file. Render Section 3 Blocking could occur here delaying the rendering of Section 3

Render Logo Render Section 1 Download File (Part 1) Download File (Part 2) Render Section 2 from file Render Section 3

 Allows us to download information from a server on an as needed basis.  Instantiate an XMLHTTPRequest object

Danger, Will Robinson, Danger!

if(browser == "Microsoft Internet Explorer"){ objAjax = new ActiveXObject("Microsoft.XMLHTTP");

if(browser == "Microsoft Internet Explorer"){ objAjax = new ActiveXObject("Microsoft.XMLHTTP");

if(browser == "Microsoft Internet Explorer"){ objAjax = new ActiveXObject("Microsoft.XMLHTTP");

getElementById must match the area of the browser that you are targeting.

StateDescription 0not initialized 1set up 2sent 3in progress 4complete A request will go through a series of states on the way to completing the request

 A small section of a page can be updated. Saves on bandwidth and loading times, and reduces server load.  The code is lightweight and not very complex.  JavaScript and the XMLHttpRequest object are supported in all modern browsers

 It's got the geeky cool factor ;-)