function addEvent(obj, evType, fn){
	if (obj.addEventListener){
		obj.addEventListener(evType, fn, false);
		return true;
	} else if (obj.attachEvent){
		var r = obj.attachEvent("on"+evType, fn);
		return r;
	} else {
		return false;
	}
}

function removeEvent(obj, evType, fn, useCapture){
	if (obj.removeEventListener){
		obj.removeEventListener(evType, fn, useCapture);
		return true;
	} else if (obj.detachEvent){
		var r = obj.detachEvent("on"+evType, fn);
		return r;
	} else {
		//alert("Handler could not be removed");
	}
}