function addEvent(elm, evType, fn, useCapture)	{
// cross-browser event handling for IE5+, NS6+ and Mozilla/Gecko
// By Scott Andrew
	if(elm.addEventListener)	{
		elm.addEventListener(evType, fn, useCapture);
		return true;
	} else if(elm.attachEvent)	{
		var r = elm.attachEvent('on' + evType, fn);
		return r;
	} else	{
		elm['on' + evType] = fn;
	}
}