Allora quando sono on line non trova il file XML, perchè??

codice:
getEvents.onLoad = function (success) {
if (success){
	// calendar_array will hold the calendar data that has been loaded
	var calendar_array = new Array();
	var minStartDate = this.firstChild.attributes.startDate.parseDate();
	var maxEndDate = this.firstChild.attributes.endDate.parseDate();
	// minStartDate and maxEndDate are used to set the displayRange
	calendar_ec. setDisplayRange({begin:minStartDate,end:
maxEndDate});
	// loop over the event nodes in the xml
	// and stores the record as an object inside calendar_array
	var qNodes = this.firstChild.childNodes;
	for (var q=0; q<qNodes.length; q++) {
		var d = qNodes[q].attributes;
		calendar_array.push({title:d.title,description:d.description,startDate:d.startDate.parseDate(),endDate:d.endDate.parseDate(),allDay:Boolean(d.allDay),eventType:d.eventType,pattern:qNodes[q].firstChild});
	}
	// passo l' array del calendario
	calendar_ec.setDataProvider(calendar_array);
	// show the calendar now it is ready
	calendar_ec._visible = true;
	// simulo il click su ogni giorno del calendario
	calendar_ec.getDayByDate(new Date().getDate()).onRelease();
}else{
events_txt.htmlText = "non trvo il file XML"
}
}
// Carico il file XML
getEvents.load("calendario.xml");
in fatti non lo trova, ma è su, come mai? Cosa puo' essere? Servono diritti particolari o robe simili per leggere on line un file XML??