title: Contact form 7 call submit event in jQuery
body: <p>I have a simple contact form and in the end I added a custom field:</p>
  
  <pre><code>&lt;input type="text" name="test" id="test" class="form-control"&gt;
  </code></pre>
  
  <p>I need to check field is empty and then submit form:</p>
  
  <pre><code>$('.wpcf7-submit').on('click', function (e) {
      e.preventDefault();
  
      var testInput = $('input[name="test"]').val();
  
      if (testInput != '') {
          // How to submit form here?
      }
  });
  </code></pre>
  
  <p>How to do it?</p>