ASP.NET: Adding check/uncheck all button with a gridview.

It is a common question for many developers that
1) How to add a checkbox that appears with each row of a gridview.
2) How to implement check/uncheck all functionality.

I found a useful tutorial on the internet which pretty much covers both of the above questions.
Take a look at this here:

http://wiki.asp.net/page.aspx/281/check-uncheck-checkboxes-in-gridview-using-javascript/

** I believe when there are so many quality tutorials over the web, I do not really need to write one of my own unless the topic is something unique**