text: (function() {
    'use strict';
  
    // Define values for keycodes
    var VK_ENTER      = 13;
    var VK_SPACE      = 32;
    var VK_LEFT       = 37;
    var VK_UP         = 38;
    var VK_RIGHT      = 39;
    var VK_DOWN       = 40;
  
    // Helper function to convert NodeLists to Arrays
    function slice(nodes) {
      return Array.prototype.slice.call(nodes);
    }
  
    
  
    function RadioGroup(id) {
      this.el = document.querySelector(id);
      this.buttons = slice(this.el.querySelectorAll('.radio'));
      this.focusedIdx = 0;
      this.focusedButton = this.buttons[this.focusedIdx];
  
      this.el.addEventListener('keydown', this.handleKeyDown.bind(this));
    }
  
    RadioGroup.prototype.handleKeyDown = function(e) {
      switch(e.keyCode) {
  
        case VK_UP:
        case VK_LEFT: {
  
          e.preventDefault();
  
          // This seems like a good place to do some stuff :)
          if (this.focusedIdx === 0) {
            this.focusedIdx = this.buttons.length-1;
          }
          else {
            this.focusedIdx--;
          }
  
          break;
  
        }
  
        case VK_DOWN:
        case VK_RIGHT: {
  
          e.preventDefault();
  
          // This seems like a good place to do some stuff :)
          if (this.focusedIdx === this.buttons.length-1) {
            this.focusedIdx = 0;          
          }
          else {
            this.focusedIdx++;
          }
  
  
          break;
        }
  
      }
  
      this.changeFocus(this.focusedIdx); // <-- Hmm, interesting...
    };
  
    RadioGroup.prototype.changeFocus = function(idx) {
      // Set the old button to tabindex -1
      this.focusedButton.tabIndex = -1;
      this.focusedButton.removeAttribute('checked');
  
      // Set the new button to tabindex 0 and focus it
      this.focusedButton = this.buttons[idx];
      this.focusedButton.tabIndex = 0;
      this.focusedButton.focus();
      this.focusedButton.setAttribute('checked', 'checked');
    };
  
    var group1 = new RadioGroup('#group1');
  
  }());
  