Steps to setup AJAX on Sharepoint Server 2007

1. Download ASP.NET 2.0 AJAX Extensions 1.0 from http://ajax.asp.net/default.aspx
2. Install ASP.NET 2.0 AJAX Extensions 1.0 on the server.
3. Update web.config file of the server as directed in http://ajax.asp.net/docs/ConfiguringASPNETAJAX.aspx
4. Script manager has to be added to enable AJAX on webpage,

• It can be added in master(template) page to enable the whole website to be AJAX enabled
  
• The class AjaxBasePart.cs found in http://www.capdes.com/2007/02/microsoft_office_sharepoint_se.html can be used as base class of our class.
  
• Adding Script Manager to our class.

Thats it. Now you can create your own AJAX enabled solutions.

Videos for introduction and implementation of AJAX can be found at http://www.asp.net/learn/videos/default.aspx

There are a lot of AJAX enabled controls (ASP.NET AJAX Control Toolkit) available at http://ajax.asp.net/downloads/default.aspx which can be used directly on our website as like as custom user control.

Have fun.