Using ExternalInterface.addCallback() we can expose an actionscript function and make it available to javascript. This would be helpful to have your webpage with embedded flash communicate to your flash swf file and even control it with javascript! Say we wanted to have buttons in the html page that would control an object in the flash. Communication is a two-way road so wouldn’t it be great to be able to go the other way as well, you can! That is the main function of ExternalInterface! In this example/tutorial I will explain both directions of communication with flash and javascript!