How to add AjaxControlToolkit dll to your Web Application and how to add its controls to Toolbox?

I have provided definition of AJAX in the following post :

http://aspdotnetandmssqlserver.blogspot.com/2016/08/concepts.html

Here I will explain the steps of how to add AjaxControlToolkit dll to our Web
Application in order to use its controls in web pages.

First is to add its reference to our project. For that the steps are the following :

(1) Download AjaxControlToolkit

(2) Copy AjaxControlToolkit.dll to Project's "Bin" folder.

(3) Next is to provide its reference to the Application. For that Right click
      on Solution Explorer and click "Add Reference...", a window will open like this

(4) Browse to the dll in the Bin folder and click OK.

Now AJAX can be used in our Application.

Next I will explain how to add AJAX Controls to Toolbox :

For that the steps are the following :

(1) Right click on the Toolbox plain area and click "Add Tab" and provide name
For eg: "AJAX Controls".

(2) Right click on the new tab , "AJAX Controls" and click "Choose items...".
Then a window of "Choose Toolbox Items" will appear like this :

(3) Browse to the dll inside project's Bin folder and click Ok

(4) Then again click Ok. Then You can see AJAX Tab populating with its controls
like this :

Now its ready to add and use AJAX Controls in your Website or Web Application.