function addEvent(elm, evType, func, useCapture) {
	if (elm.addEventListener) {
		elm.addEventListener(evType, func, useCapture);
		return true;
	} else if (elm.attachEvent) {
		var r = elm.attachEvent('on' + evType, func);
		return r;
	} else {
		elm['on' + evType] = func;
		return true;
	}
}