ExternalInterface Call

I need to upgrade some AS 2.0 code and could use some help.

In my HTML pages I have a short JS script that looks like this:

<script language="JavaScript" type="text/javascript">
function startImage(name) { 
    return 3; 

And within the old AS 2 code:

            var testVarTxt:TextField = new TextField();

            var getString:String;
            // Communicate with the Javascript function "startImage"
            getString = String(ExternalInterface.call("startImage", name));
            // Change the string value to a number
            var JStoFlash:Number = parseInt(getString);
            testVarTxt.text = JStoFlash;

Does someone know how to rewrite this for AS 3? I need to use something like parseInt to convert the string to an integer, and, I’m not sure if I’m using the ExternalInterface call() in the correct manner for AS 3.0.