Making IE9 Extension button pulse

I am wanting to make an IE9 extension where I add an icon to the toolbar.

When I detect a given element on the page (lets say flash content) I want the icon to become enabled and have its color pulse (or some other slight animation that draws the users attention).

How to get started with developing Internet Explorer extensions?

I'm currently using the abo开发者_如何学运维ve as a reference, given that how would I do this?