I have a responsive django app that shows a phone number on a button click. I'd like to trigger the phone call on mobile devices. How do I detect the device such that the call to phone action only happens on mobile devices, but on desktop it only shows text? I've seen this post How to trigger a phone call when clicking a link in a web page on mobile phone but it doesn't help much.
 <input onclick="change()"  class="btn btn-primary phone" type="button" value="Show Phone Number" id="myButton1" />
      <script type="text/javascript">
      function change() 
      {
        var elem = document.getElementById("myButton1");
        elem.value = "" + {{contact_no}};
      }
      </script>
 
     
     
    