docs: function(xhr){
  			if (xhr && (xhr.readyState == 4)) {
  				if (xmlloader.httpSuccess(xhr)) {
  					processResponse(xhr);
  				}
  				else { //if it failed, it mighht be that the source has no CORS enabled. In such case, fallback to proxy before erroring
  					if(usingCORS && xmlloader.proxyURL) { //if it failed when using CORS and we've got a proxy, try to get the data via the proxy
  					  xhr=undefined;
  					  usingCORS = false;
  					  var new_xhr = xmlloader.xhr();
  					  new_xhr.open('GET', xmlloader.proxyURL+'?url='+url, true);
  					  new_xhr.onreadystatechange = function() {change(new_xhr);}
  					  new_xhr.send(null);
  					} else {
  					  errorcallback && errorcallback({id: "xmlhttprequest_error", msg: xhr.status});
  					}
  				}
  				//to prevent IE memory leaks
  				xhr = undefined;
  			} 
  		}