How do I communicate between an AIR application and a Flex application loaded through an HTMLLoader in AIR?

I have been trying to use LocalConnection, however I am getting an invalid argument error, so Im questioning whether or not this LocalConnection approach is even right:

AIR Application:

public function init() {

                var conn:LocalConnection;

                conn = new LocalConnection();

                conn.allowDomain("localhost");

                conn.connect("connection1");

                loadHTML();

}

private function loadHTML() {

                var urlReq:URLRequest = new URLRequest("http://localhost/myapp/");

                htmlUI.htmlLoader.load(urlReq);   

                visible=true;        

                //set attribute to allow external links to open in default system browser

                htmlUI.htmlLoader.navigateInSystemBrowser = true;

}

public function connect():void {

                trace("LOCAL CONNECTION SUCCEEDED");

}

FLEX Application:

private function doSomethingOnClick() : void {

    var conn:LocalConnection;

    conn = new LocalConnection();

    try {

        conn.send('app#MyAirApplication:connection1', 'connect');

    } catch (error:ArgumentError) {

        TIAlert.error(error.getStackTrace())

    }

}