title: Enable/Disable button by selected value in drop down list using AngularJS
body: <p>I have one button called test and one drop-down menu with three values.
  How to enable-disable Test button according to value selected in drop down menu.
  Eg. If selected "Not Ready" , button should disable
      If selected Ready or Attention, button should enable</p>
  
  <pre><code>&lt;div class="row"&gt;
      &lt;div&gt;
      &lt;button id="testBtn" class="btn btn-default" &gt;Test&lt;/button&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  
  
  &lt;div class="row"&gt;
  &lt;div class="col-md-12"&gt;
  
  
      &lt;select name="select"&gt;
          &lt;option value="value1" selected&gt;Not ready&lt;/option&gt; 
          &lt;option value="value2"&gt;Ready&lt;/option&gt;
          &lt;option value="value3"&gt;Attention !!&lt;/option&gt;
      &lt;/select&gt;
  
  
   &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>See <a href="http://plnkr.co/edit/suRIVHWECXYdtYy5tbbd" rel="nofollow">Plunker</a></p>