quick question on xhr2 upload events

My reading of http://www.w3.org/TR/XMLHttpRequest2/#tracking leads me
to believe that you can do this:

xhr.upload.addEventListener("progress", function(){}, false);

but not this:

xhr.upload.onprogress = function(){};

That is, XMLHttpRequestUpload implements EventTarget, but not any
old-style event handler function properties. Is that correct?

- a