function shuffle(array) {
  let currentIndex = array.length,  randomIndex;

  // While there remain elements to shuffle...
  while (currentIndex != 0) {

    // Pick a remaining element...
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex--;

    // And swap it with the current element.
    [array[currentIndex], array[randomIndex]] = [
      array[randomIndex], array[currentIndex]];
  }

  return array;

}

function getParam(parameterName) {
  var result = null,
      tmp = [];
  location.search
      .substr(1)
      .split("&")
      .forEach(function (item) {
        tmp = item.split("=");
        if (tmp[0] === parameterName) result = decodeURIComponent(tmp[1]);
      });
  return result;
}