htmlloader - set parameter in js [AIR]

Maybe my question is not clear. More:

test.html

<script>
   var param = 0;
</script>

as3

htmlString = File.documentsDirectory.resolvePath("test.html");

createHtmlLoader(htmlString.nativePath);

private function createHtmlLoader(url:String):void {  
  html = new HTMLLoader();
   var urlReq:URLRequest = new URLRequest(url);
  html.width = 550;
  html.height = 400;
  html.addEventListener(Event.COMPLETE, onLoad);
  html.load(urlReq);
}

private function onLoad(e:Event):void {

  var document = html.window.document;
 

  //!! in trace: param = 0
  trace(html.window.param);

   //!! set param = 1
  html.window.param = 1;

   //!! in trace: param = 1; ok
  trace(html.window.param);

  trace(document.documentElement.outerHTML);
   //!! in trace: param = 0; Why?
}

When i want to get the whole document: document.documenElement.outerHTML

JS script remains unchanged.