title: Enable submit button after all droppable div is filled
body: <p>I am making one quiz using jquery. below is the screen snap.</p>
  
  <p><a href="https://i.stack.imgur.com/bxWYe.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/bxWYe.png" alt="enter image description here"></a></p>
  
  <p>This quiz is drag and drop kind of quiz. all work is done and successful.  Now I have an issue regarding <strong>enable submit button</strong>. </p>
  
  <p><strong>Requirements are</strong></p>
  
  <ol>
  <li>A button must be disabled when page load - done</li>
  <li>options should be draggable and droppable in blank space - done</li>
  </ol>
  
  <p><strong>What is not done?</strong></p>
  
  <p>after <strong>both</strong> items get dragged in blank space button should be enabled </p>
  
  <p>please see my jquery regarding this. and tell me where I am making mistake</p>
  
  <pre><code>    jQuery(document).ready(function () {
          jQuery('.selected_answer1' &amp;&amp; '.selected_answer2').on('drop change', function (event, ui){ 
            alert('dropped');
              if (jQuery(this).drop()) {
                  jQuery('.fillinblank_button').prop('disabled', false);
                  alert('dropped')
              }
              else {
                  jQuery('.fillinblank_button').prop('disabled', true);
              }
          });
  });
  </code></pre>
  
  <p><strong>about class name</strong> - </p>
  
  <p>.selected_answer1 - 1st blank space</p>
  
  <p>.selected_answer2 - 2nd blank space</p>
  
  <p>.fillinblank_button - submit button</p>
  
  <p><strong>Jsfiddle link</strong> - <a href="https://jsfiddle.net/vaishuk/ajmuse3v/" rel="nofollow noreferrer">https://jsfiddle.net/vaishuk/ajmuse3v/</a></p>
  
  <p>PS - I want to do this with jquery, not js. </p>
  
  <p>Thank you.</p>