title: Check $pristine status of ngModel without using a form
body: <p>Am trying to figure out how to check the state of a ngModel without using a form tag. I don't have wrappers is just basic input element with a ngModel. </p>
  
  <p>All the examples I have found so far are for form validations and in this case, there is no form.</p>
  
  <p>When i tried something like:</p>
  
  <p>HTML</p>
  
  <pre><code>&lt;input type="text" ng-model="lastname"&gt;
  </code></pre>
  
  <p>SCRIPT:</p>
  
  <pre><code>if($scope.lastname.$dirty) {
    console.log('last name has changed');
  }
  </code></pre>
  
  <p>I get undefined.</p>
  
  <p>Is there a way to check the state of the ngModel without adding a watch directive to it? it seems it would be something basic that is part of the framework. Why wouldn't this work?</p>