AJAX interview questions part -III

25. What is the role of the ScriptManagerProxy control?

A Web page cannot contain more than one ScriptManager control. You can use the ScriptManagerProxy control to add scripts to other pages; however to perform such an operation, you need to work with a master page that contains the ScriptManager control. If you have only few pages that need to register to a script or a Web service, then you should remove these pages from the ScriptManager control and add them as individual pages by using the ScriptManagerProxy control. If you include the scripts on the master page by the ScriptManager control, then the items get downloaded on each page that extends the master page, even if they are not necessary.

26. What is the work of the ConformOnFormSubmit property in the ConfirmButtonExtender control?

The ConformOnFormSubmit property determines whether or not the confirm dialog box should wait when the form is submitted for display.

27. What is the syntax to create AJAX objects?

AJAX uses the following syntax to create an object:


var myobject = new AjaxObject("page path");
The page path is the URL of the Web page containing the object that you want to call. The URL must be of the same domain as the Web page.

28. Is there any difference between HTML and XHTML?

Extensible HTML (XHTML) is a markup language that provides the mixture expressions of HTML and XML. XHTML is a flexible markup language that enables automated processing by standard XML tools, which was difficult in HTML.

29. What are the requirements to run ASP.NET AJAX applications on a server?

AJAX is a built-in functionality of .NET Framework 4.0. Therefore, you can run an AJAX application by just installing Microsoft Visual Studio 2010. However, to use extenders in your applications, you are required to install AJAX Control Toolkit and copy the AjaxControlToolkit.dll file to the Bin directory of your application.

30. Describe the situations in which AJAX should not be used.

You should not use AJAX if:

• You want the page to show in a search engine, such as Google, because WebCrawler does not execute JavaScript code.
• The browser does not support JavaScript.
• You want to create a secure application

31. What is the use of the ScriptManager control in AJAX?

The ScriptManager control is a core control that performs a key role in implementing the ASP.NET AJAX functionality. It helps to use JavaScript for the Microsoft AJAX Library. It should be noted that AJAX Library on a Web page can only be used if the Web page contains the ScriptManager control. This control makes use of the ScriptManager class to maintain the AJAX script libraries and script files. It allows for partial page rendering, Web service calls, and use of ASP.NET AJAX Client Library by rendering the AJAX Library scripts to the browser.

32. How can you find out that an AJAX request has been completed?

You can find out that an AJAX request has been completed by using the readyState property. If the value of this property equals to four, it means that the request has been completed and the data is available.

33. Is it possible to use multiple ScriptManager controls on a Web page?

No, it is not possible.

34. What are the new controls introduced in ASP.NET AJAX Control Toolkit?

The following controls are introduced with the new version of AJAX Control Toolkit:

• SeaDragonExtender control - Refers to the control that is used to deeply zoom the images. You can zoom in or out the image or the particular portion of the image by using the mouse. You can also create a menu over the Seadragon control. This control is helpful when you want to analyze the image closely.
• AsyncFileUploadExtender control - Refers to the control that provides the facility to upload and save the files on the server asynchronously. You can check the outcome either at the server or client side.

35. Briefly describe ASP.NET AJAX Framework.

ASP.NET AJAX Framework provides a platform where developers can develop such type of applications that use the AJAX concept. The AJAX provides the collection of technologies to create dynamic pages at the client side. The JavaScript requests are responsible to retrieve data from the server or send data to the server. Even some processing at server also requires handling requests, such as searching and storing of data. These tasks are achieved more easily using the AJAX Framework.


AJAX Framework is completely devoted to process requests. The objective of the AJAX engine is to reduce the delays that the user notices while performing a postback to the server. AJAX Framework allows JavaScript functions to send requests to server at the client side. On the other side, it allows the server to process the client's request, searches data, and responds the result to the browser.

36. Is the AjaxControlToolkit.dll file installed in the Global Assembly Cache?

No, you have to copy this file to the Bin folder of your application.