Tell SWF Studio about an HTTP.read event that you'd like to receive notifications for.
First available in version 3.0 build 2039.
event - The name of the event you want notification enabled for. Valid values include: onProgress.
result - Notification data for the specified event (see description of events for more detail).
When this method is called synchronously, a return object containing the output parameters is returned to the caller immediately.
name - onProgress
type - periodic
result - "bytes_transferred"
function onHTTPProgress(ret_obj, cb_obj, err_obj)
ssDebug.trace("total bytes transferred: " + ret_obj.result);