title: Get the child input tag for the current checkbox clicked
body: <p>I am trying to get the child input tag for the current checkbox that is clicked and add <code>checked</code> to it through my directive. I have the directive setup correctly but I am getting <code>undefined</code> when I try to get <code>elem[1]</code></p>
  
  <p>HTML:</p>
  
  <pre><code>&lt;div class="checkbox"&gt;
      &lt;input id="checkbox1" type="checkbox" checked ng-model="checkboxoption.value1"&gt;
      &lt;span class="custom"&gt;&lt;/span&gt;
      &lt;label for="checkbox1"&gt;Checkbox 1&lt;/label&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>JS:</p>
  
  <pre><code>.directive('checkbox', [function() {
      return {
          restrict: 'C',
          scope: {},
          link: function(scope, elem, attr) {
              elem.bind('click', function(evt) {
                  var currentCheckbox = elem[1];
                  console.log(elem[1]);
                  elem.prop('checked');
              });
          }
      };
  }])
  </code></pre>