title: How to $setdirty to a single input
body: <p>I've got a little problem. I want to set to dirty a single input, I mean, because when I give a value automatically it stays in <code>pristine</code> class, doesn't change, and doesn't save the new value.</p>
  
  <p>If I edit it, it works and change the class. I want to cancel that <code>pristine</code> class.
  If anyone know please let me know.</p>
  
  <pre><code>&lt;form class="form-horizontal" ng-repeat="studiant in studiants" name="form" id="form"&gt;
  
    &lt;input type="hidden" name="id" value="{{studiant.studiant_id}}" class="form-control" disabled&gt;
  
    &lt;div class="form-group"&gt;
      &lt;label for="school" class="col-md-2 control-label"&gt;School&lt;/label&gt;
      &lt;div class="col-md-1"&gt;
        &lt;input type="text" id="school" name="school" class="form-control" ng-init="studiant.school=studiant.studiant_school" ng-model="studiant.school"&gt;
      &lt;/div&gt;
    &lt;/div&gt;
    &lt;div class="form-group"&gt;
      &lt;label for="name" class="col-md-2 control-label"&gt;Student's Name&lt;/label&gt;
      &lt;div class="col-md-10"&gt;
        &lt;input type="text" id="name" name="name" class="form-control" ng-init="studiant.name=studiant.studiant_name" ng-model="studiant.name"&gt;
      &lt;/div&gt;
    &lt;/div&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>And the script:</p>
  
  <pre><code>document.getElementbyId('name').value = "anything";
  </code></pre>
  
  <p>Or, if I doing wrong and I have to change the <code>value</code> with <code>ng-model</code> or something, please help me.</p>