title: External Interface Error
body: <p>This is the code I am using to call a function <code>calc</code> in javascript:</p>
  
  <pre><code>import flash.external.ExternalInterface;
  
  ExternalInterface.addCallback("asFunc", this, asFunc); 
  
  function asFunc(str:String):Void {
      out.text = "JS &gt; Hello " + str;
  }
  
  send_btn.addEventListener(MouseEvent.CLICK, clickListener);
  
  function clickListener(eventObj:Object):Void {
      trace("click &gt; " + mean.text);
      ExternalInterface.call("calc", mean.text);
  }
  </code></pre>
  
  <p>but I get the following error: </p>
  
  <blockquote>
    <p>1046: Type was not found or was not a compile-time constant: Void.</p>
  </blockquote>
  
  <p>What am I doing wrong here? (I modified the example on live docs.)</p>