you said: I am a newbie to AJAX. I want to use AJAX without toolkit controls such as UpdatePanel,UpdateProgress, etc.
A very common misconception is the difference between idea (knowledge) and tool-set. This is a classic case. You want to use AJAX but don't want the AJAX toolkit. AJAX is an idea, concept, method, way of solving a problem where are the AJAX toolkit is Microsoft's implementation.
You need to start by learning what is AJAX, in fact you can use AJAX with out the AJAX toolkit and there are other toolkits as well out there. Once you get the concept in your head you decide how you want to use it. May be in your case you don't need any toolset, or may be you want to reuse one out there already.
While you are out there, I would encourage you to look at
jQuery [
^]as well.
By the way here few resources for AJAX
http://en.wikipedia.org/wiki/Ajax_(programming)[
^]
http://www.w3schools.com/Ajax/Default.Asp[
^]