I apologize for the delay in responding. I had been working on a solution for building certificates in Flash that can be inserted into Adobe Captivate and Presenter. I realize your query is on an "exit" button - but that was part of the solution I created...
You could easily create a flash-based button that you could insert into Presenter that attempts to exit the course. However, that won't necessarily work in all browsers and environments. To be clear, my solution doesn't either, but there is more to it than that.
Another issue is that IF you are launching the content from an LMS (e.g. Connect) it's possible that there are still LMS communications that need to occur before the file is closed. That's something that is difficult to describe programatically.
However, I did create a solution for you that may work. I have just released a SWC component and an article with a series of examples here: http://www.connectusers.com/tutorials/2 … /index.php
I recommend reviewing the article and downloading the different examples on Certificates in Flash for Quitting. They show how you can use my component to create a Flash-based button to quit the content (or attempt to automatically quit when the page that contains the Flash file is reached). The method I created attempts to wait for the LMS queue to be empty before it attempts to close the browser.
If you import one of my example files into Adobe Presenter (or Captivate) you might be able to see if this solution works for you.