How can I develop an event using class module that can detect if
current windows has been scrolled. either by using scroll bar or mouse
wheel.

I know little bit about class modules and develop a test event using
raise event and with event commands.

I read and used the article on the following link but still now sure
how to do this with scroll bar.

http://www.tushar-mehta.com/excel/vb...xl%20event.htm