text: function humanReadableSize(bytes) {
      units = ['Bytes', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB']
  
      var i = Math.floor(Math.log(bytes) / Math.log(1024))
  
      if (i > units.length - 1) {
          i = units.length - 1
      }
  
      bytes = bytes / Math.pow(1024, i)
      return bytes.toFixed(2) + ' ' + units[i]
  }
  
  function validateFileSize(input, min, max, message) {
      var size = input.files[0].size;
      var small = (min > 0) && (size < min);
      var large = (max > 0) && (size > max);
      if (small || large) {
          message = message || "File size ({size}) is too "
          message += small ? "low" : "large";
          message += ". Please upload a file of at "
          message += small ? "least" : "most";
          message += " {limit}."
          alert(message.replace('{size}', humanReadableSize(input.files[0].size)).replace('{limit}', humanReadableSize(small ? min : max)));
          input.value = '';
      }
  }
  