UL(node, threshold) {
  var lis = node.childNodes;
  var l = lis.length;

  var count = 0;
  for ( var i = 0; i < l ; i++ ) {
    count = count + setThresholdLI(lis[i], threshold);
  }

  var visible = (count > 0) ? 1 : 0;
  if (visible) {
    node.style.display = 'block';
  }
  else {
    node.style.display = 'none';
  }
  return visible;
}

function toggleChildren(img, event) {
  event.cancelBubble=true;

  if (img.src.indexOf('empty.png') > -1)
    return;

  var minus = (img.src.indexOf('minus.png') > -