You should be able to click off of the modal and it should disappear. The only issue I see with doing it that way is if you are in another Window and click to

You should be able to click off of the modal and it should disappear. The only issue I see with doing it that way is if you are in another Window and click to get focus, but you should deal with the alert when it appears since it is a part of completing a task. Usually people only switch windows when they have completed a task.