Explain ASP.NET Ajax Framework.

Answer
ASP.NET Ajax Framework is used for implementing the Ajax functionality. It allows you to create interactive web applications which can update data on the web page without changing the actions of the existing page. The frame work includes both client and serer side components. The framework can be used best in ASP.NET 2.0.

Explain limitations of Ajax.

Answer

• Back functionality cannot work because the dynamic pages don’t register themselves to the browsers history engine. Hence the need of Iframe becomes essential.
• The page cannot be bookmarked if implemented using Ajax.
• If java script is disabled , Ajax will not work
• Because different components of the pages are loaded at different times, response time may be slow.
• Because different components of the pages are loaded at different times it may create confusion for the user. 

What is the role of Script Manager in Ajax?

Answer
Script Manager, as the name suggests is used to manage the client side script of Ajax. Since Ajax uses Java Script, there needs to be a mediator to manage this script and restrict a particular version to a browser. A Script manager is present on every page where Ajax is used to enable the Ajax Libraries. These Libraries in turn helps to implement the core Functionality of Ajax: Partial rendering.  

List out differences between AJAX and JavaScript.

Answer
Ajax is Asynchronous Java Script and XML. Here on sending request to the server, one needn’t wait for the response. Other operations on the page can be carried out. Hence, Asynchronous. On the other hand, Java script sends an HTTPRequest to the server and waits for the XML response. 

E.g. populating State field. Using JavaScript we need to use the “Onchnage” event where as using ajax, the request is just sent to populate the state list. Other operations can be carried out on the page. 

Ajax is a part of Java Script programming. Java Script is used to manage and control a web page once downloaded. Ajax does not need to wait for the whole page to download. 

Use of Ajax can reduce connections to the server since the script has to be requested once