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