A naive way of doing something

naive.js

var toArray = function(orig) {
  var arr = [];
  for (var i = 0; i < orig.length; i++) {
    arr.push(orig[i]);
  }
  return arr;
}

var find_child_by_class = function(root, klass) {
  var queue = toArray(root.children);
  var head = null;
  while (queue.length > 0) {
    head = queue.shift();
    if (head.className === klass) {
      return head;
    } else {
      queue = queue.concat(toArray(head.children));
    }
  }

  return null;
}

setInterval(function() {
  // Nah, you can easily figure out what goes here
}, 15000)