Here’s a quick snippet of code for setting up intercommunication between a SWF and JavaScript, using ExternalInterface:
import flash.external.ExternalInterface; // Calling a JavaScript function from AS3 (with optional parameters) if (ExternalInterface.available) ExternalInterface.call("javascriptFunction", param1, param2); // Implementing a JavaScript callback in AS3 (flashFunction is called when JavaScript calls javascriptFunction) if (ExternalInterface.available) ExternalInterface.addCallback("javascriptFunction", flashFunction);