preloading xml with setInterval

Hi guys,
i'm trying to preload xml data.
but it don't work and i can't clear the interval.
any ideas?
thanx,
noir

PHP Code:

---

loadingXml = function(xmlObject) {     
    if (xmlObject.getBytesLoaded() == 0) {
        return;
    }
    var loaded = xmlObject.getBytesLoaded();
    var total = xmlObject.getBytesTotal();
    var percent = Math.floor((loaded/total)*100);
     trace(percent);
}

xmlObject = new Xml();

xmlObject.onLoad(){
      clearInterval(ID);
      trace("xml data loaded")
}
xmlObject.load("test.xml");
ID = setInterval(loadingXml, 50, xmlObject); 


---

instead of :
xmlObject.onLoad() (wrong)

use :
xmlObject.onLoad = function() (this is correct one )

thanx, for reply.
I made that little sintax error.
bye
noir