XmlHttpREquest

Hi

I made  a chrome over gecko

I trace the states of my Http(s) and Files requests using OnStaeChange
and onLocationChange.

Now I start with Ajax XmlHttpRequest.

If I use the following code into a javascript function

		function getSynchronousContentByAjax(url) {

			httpRequest = new XMLHttpRequest();
			httpRequest.open('GET', url, false);
			httpRequest.send(null);

			return httpRequest.responseText;
		}

It works OK and I can replace the text into a div by the text got from
the URL.

But I have no trace about the call to the URL , no trace from
onStateCHange or from onLocationCHange

I saw that there is an interface nsIXmlHttpREquest. Have I to use it ?

Do you have samples

thank's a lot
philippe