title: both myForm.$valid & myForm.$invalid are undefined on angular form?
body: <p>I have a form named <code>myform</code> &amp; I'm trying to set <code>ng-disabled</code> with this code:</p>
  
  <pre><code>ng-disabled="myForm.$invalid"
  </code></pre>
  
  <p>but both <code>myForm.$invalid</code> &amp; <code>myForm.$valid</code> are undefined.  What is the issue exactly?  I checked in console &amp; <code>myForm</code> is correctly set to the form.</p>
  
  <p><strong>UPDATE</strong></p>
  
  <pre><code> &lt;form id="commissionForm" name="myForm" class="form-horizontal"&gt;
  
              &lt;div class="form-group"&gt;
                  &lt;div class="col-sm-8 col-md-8 col-lg-8 col-xs-8" /&gt;
                  &lt;div class="col-sm-2 col-md-2 col-lg-2 col-xs-2" &gt;
                      &lt;button name="NextBtn" id="NextBtn"
                              ng-class="{disabled:commissionForm.$invalid}"
                              ng-disabled="myForm.$invalid"
                              ng-click="nextBtnClicked()" class="btn btn-primary"
                              &gt;Next&lt;/button&gt;
                  &lt;/div&gt;
              &lt;/div&gt;
   &lt;/form&gt;
  </code></pre>