 <p>A very simple way would be to change the Flash movie in this manner:</p> <p>When the movie loads (in the load listener in AS), add this</p> <pre><code>if(ExternalInterface.available) { ExternalInterface.call(flashReady); } </code></pre> <p>and in the javascript, have a function called flashReady which does the thing it needs to</p> <pre><code>function flashReady() { //Your awesome function body here } </code></pre>