External Interface in Flex - Running Javascript in Flex

External Interface

The ExternalInterface class enables  communication between ActionScript and Flash Player containers such as an HTML page containing JavaScript and an embedded SWF file, or an application that has the Flash Player embedded in it. The communication is available in both directions. An HTTP/JavaScript page can call an ActionScript function which can return data that the JavaScript can use or ActionScript can call Javascript.

ActionScript can call any JavaScript function passing arguments and receiving a return value from the JavaScript function.  JavaScript on the HTML page can easily call an ActionScript function complete with arguments and return values.

 External.mxml

 <?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"  horizontalAlign="center" verticalAlign="middle">
    <mx:Script>
        <![CDATA[
          
            public function showmes():void{
            ExternalInterface.call("alert('A javascript Message')");
            }
          
        ]]>
    </mx:Script>
    <mx:Button id="Eibtn" click="showmes();" label="click me"/>

</mx:Application>

Rendered Example