ActionScript 3.0 :: Passing Variables Via POST To A New Page...

I need to open a new page from Flash, using navigateToURL(...)

I need to send a variable to this newly opened html page that does not appear within the url as a query string, so i'm using POST.

However each time I try it the variables appear within the query string... what am I doing wrong?


ActionScript Code:
var link:String = "test.html";

var urlVars:URLVariables = new URLVariables();
urlVars.username = "username";

var urlRequest:URLRequest = new URLRequest(link);
urlRequest.data = urlVars;
urlRequest.method = URLRequestMethod.POST;
urlRequest.contentType = "application/x-www-form-urlencoded";

navigateToURL(urlRequest, "_blank");

Cheers,

Matt / MSFX