While working on a few PhotoSnack albums a few days ago, I’ve tested some features with several browsers but noticed that with Internet Explorer the albums were not working as supposed to. Specifically, the ExternalInterface.call() function wasn’t calling the target JavaScript functions at all.
After testing the JavaScript and ActionScript functions separately, it seemed they all worked without any problems. Anyway, the JavaScript functions were being called with no problems on all the other browsers I tested, except on Internet Explorer. After searching the problem on the Internet I came upon a comment on the ActionScript 3 documention posted on Adobe’s livedocs for the ExternalInterface class (thanks gerdy).
It looks like for the ExternalInterface.call() function to work in IE, the embedded Flash object MUST have the id attribute specified. Otherwise you won’t be able to display not even a JavaScript alert message from Flash. As soon as the id attribute was set for the flash objects in PhotoSnack, the albums worked just fine with Internet Explorer too.
So, as a best practice, I recommend always setting the id attribute of your Flash objects embedded in HTML pages.