Alfresco Flex AIR Upload File Basic Authentication Error

See the wiki page for the Alfresco Upload Webscripts, but with these files, I was unable to upload files without always getting the Basic Authentication popup window always appearing. The key was adding the 'alf_ticket' request parameter to the URL string:

fileRef = new FileReference(); //instantiated earlier

urlVars = new URLVariables();
urlVars.title = 'my title';
urlVars.desc = 'my description';

urlReq = new URLRequest();
urlReq.method = URLRequestMethod.POST;
urlReq.data = urlVars;
//ticket was returned after logging in
urlReq.url = "http://<<myserver>>/alfresco/service/site/upload?alf_ticket="+this.ticket;
//
fileRef.upload(urlReq, 'file');

Login code...

var svc : HTTPService = new HTTPService();
svc.resultFormat = 'e4x'
svc.addEventListener(ResultEvent.RESULT, onLogin);
svc.url = "http://<<myserver>>/alfresco/service/api/login";
var params : Object = {};
params.u = 'bsmith';
params.pw = 'password';
svc.send(params);


  protected function onLogin(event:ResultEvent):void
  {
     this.ticket = XML(event.result).text().toString();
  }