upload file to box api v2 using as3 - actionscript-3

Question

I'm trying to upload file to box using v2. The only result i get is the error while uploading. I'm able to authenticate, get the auth token but not able to upload, I have given the code which i'm using. If i'm wrong anyway just correct me. Any help will be appreciated!!
public function upload(argFile:flash.filesystem.File):void{
argFile.addEventListener(Event.COMPLETE,
function onComplete(event:Event):void
{
trace("complete:"+event.toString());
}
);
argFile.addEventListener(IOErrorEvent.IO_ERROR,
function onIOError(event:IOErrorEvent):void
{
trace("Error:"+event.toString());
}
);
var url:String = "https://api.box.com/2.0/files/data";
// Setup the custom header
var customHeader:String = "BoxAuth api_key=" + api_key + "&auth_token=" + auth_token;
var headers:Array = [
new URLRequestHeader("Authorization", customHeader)
];
// create the url-vars
var urlVars:URLVariables = new URLVariables();
urlVars.filename1 = '#'+argFile.name;
urlVars.folder_id = "0";
// create the url-reqeust
var request:URLRequest = new URLRequest();
request.contentType = "application/octet-stream";
request.method = URLRequestMethod.POST;
// set ther url
request.url = url;
// set the header
request.requestHeaders = headers;
// set the vars
request.data = urlVars;
try {
argFile.upload(request);
} catch (e:Error)
{
trace(e.toString(), "Error (catch all)");
}
}