Ajax History & Information

AJAX, as mentioned before, is not a new programming language but a relatively new technique for creating faster, better and dynamic web applications. If you are really interested in learning AJAX, then it would be better for your learning experience if you develop some understanding of HTML, XHTML, XML and JavaScript. If you have the basic understanding of these languages then you can have a go with AJAX.

You’ll never guess what I do for a living

If we briefly look into the history of AJAX, we will come to know that the term AJAX was first coined in the year 2005, however, the techniques that helps in loading the contents of a web page dates back to the year 1996; it came when the Internet Explorer introduced the concept of IFrame element. After it, in the year 1998, Microsoft introduced another technique, called as Microsoft’s Remote Scripting that successfully replaced the older techniques. The technique involved the pulling of data through means of Java Applet which communicated with the client side using scripting language like JavaScript. Soon after it, in the year 1999, Microsoft came up with XMLHttpRequest object that acted as an ActiveX control in the Internet Explorer available at that time; IE 5. Finally, in the year 2006, the W3C (World Wide Web Consortium) announced the release of the first draft that included the specification for the object (XMLHttpRequest) and made it an official web standard.


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The main purpose of using AJAX is to enable web applications to extract data from various servers in an asynchronous manner; means that the web applications retrieve information from the server in the background without requiring the user to refresh the web page. How is data is retrieved is the basic question that most of the learners ask; this data is retrieved, asynchronously, by using the XMLHttpRequest Object or by using any Remote Scripting methods.

AJAX is basically based on the following web standards

  • XML
  • HTML
  • JavaScript
  • CSS

The main reason why AJAX is supported by all web browsers today is the fact that most of the browsers today support the web standards mentioned above; moreover, AJAX applications are not platform or browser dependent.

This document won’t make you an expert AJAX programmer; however, it will give you a general idea of how AJAX works and how the HTTP request works. Although there are no specific pre-requisite in order to learn AJAX but it is better if you have some ideas about the web standards on which AJAX is based; CSS, XML, JavaScript and HTML.

Before telling you how to make your first application in AJAX, it is worth mentioning how actually data is extracted using XMLHttpRequest object. If you have any idea about ASP or any other scripting language, then you may know that the classic method of extracting any information from the server is to

  • Make an HTML form
  • Use Get or Post in order to extract data from the server

In the classic method, the user had to click on a button; say Submit in order to send the request information, then it had to wait for the server to respond and finally a new page had to be uploaded in order to upload the HTML page with the results. The point to note here is that the Server has to return another new page every time the user send a request; resulting in slower web applications that are less user-friendly.

Now compare the classic method with AJAX; in case of AJAX, the JavaScript uses the XMLHttpRequest object in order to communicate directly with the server. Using an HTTP request, the webpage can easily request and can get response from the server without reloading or refreshing the web page; all this happens without getting into the notice of the user. The XMLHttpRequest object is supported by almost all famous web browsers like Internet Explorer, Netscape, Firefox, Opera etc.

Now, as you have learned something about AJAX, why don’t you try making your first AJAX application; it’s really not that difficult. In order to understand AJAX better, you should create a small AJAX application. Just carefully go through the following steps and you will have your first small AJAX application, but as mentioned earlier, you should have some basic knowledge about the web standards on which AJAX is based.

  • Create a Simple HTML form with two or more text fields; like UserId, UserName and UserAge. A sample is shown below

<html>
<body>

<form name=”newForm”>
ID: <input type=”Number” name=”UserId” />
Name: <input type=”text” name=”UserName” />
Age: <input type=”Number” name=”UserAge” />
</form>

</body>
</html>

  • Name your HTML file with an extension of .htm and save it.
  • Include JavaScript, in your HTML file, that will create the most important part of AJAX application; XMLHttpRequest.
  • To create an XMLHttpRequest object, you will first have to create a variable “xmlHttp” that will hold the XMLHttpRequest Object. Here is a sample of how you will create it:

xmlHttp=new XMLHttpRequest(); or you can also try the following in case of Internet Explorer
xmlHttp=new ActiveXObject(”Microsoft.XMLHTTP”);

For better learning, please visit our section of recommended forums and resources from where you can learn more about AJAX from scratch.