Why am I getting-"The ExternalInterface is not available in this container" in Flex Mobile Project

Question

I am using StageWebView to show an HTML page. I want to call a function in my flex mobile project to be called from a JS function. Using ExternalInterface, I have 
   in Flex - 
    ExternalInterface.addCallback("myFunction",myFunc);
   in JS -
        function thisMovie(movieName) {
           if (navigator.appName.indexOf("Microsoft") != -1) {
             return window[movieName];
           } else {
             return document[movieName];
       function showAlert()
              alert("Going to call AS function");
            thisMovie("ShowLocalHTML").myFunction("Hello");
              return false;
I am getting "Error: Error #2067: The ExternalInterface is not available in this container. ExternalInterface requires Internet Explorer ActiveX, Firefox, Mozilla 1.7.5 and greater, or other browsers that support NPRuntime." when trying to run the application.
And my project targets Android platform. And  I have Mozilla, Chrome installed on my desktop - although I am not user if that is relevant to the problem.
Please help in resolving this issue.

Answer 1

Is there an alternative?
I want to display a local HTML file and then allow for JS to Flex communication. I am new to Flex and AS. As per my understanding, StageWebView is the only way to
show a local HTML file in a mobile project. If the script interface is not available - then I cannot achieve JS-to-Flex communication. So is there any other way to do this??
Please help ...else I will have to abandon my foray into Flex, AS and go back to Android Java.