function changeTextSize(increment)
  {
    var el = document.getElementById("sizeableText");
    if(el.style.fontSize) {
      var size = parseInt(el.style.fontSize.replace("%", ""));
    } else {
      var size = 100;
    }
    var newSize = increment + size;
    if (newSize > 80 && newSize < 120)
    {
      el.style.fontSize = newSize + '%';
    }
  }