I am looking for a way to detect if a user has a specific extension installed in their browser (for Chrome and Firefox) Is there any way to do this? Can someone give me an example, like:

If firefox has extension Firebug then alert "Firebug is installed on this browser" if not alert "Firebug is not installed on this browser"

If Chrome has extension Angry Birds Star Wars then alert "Angry Birds Star Wars is installed on this browser" if not alert "Angry Birds Star Wars is not installed on this browser"

I understand we are not allowed to offer payment here, but I could at least give a Google AdWords $100 coupon or something for help. I would really help me out to figure out how to do this!

TIA