jQuery addClass example

Change class name on click in jQuery

HTML

<script src="http://parsleyjs.org/dist/parsley.min.js"></script>
<form id="demo-form">
  <h2>Form</h2>
  <input type="text" required value="" />
  <button type="submit">SUBMIT</button>
</form>
<br />
<span id="banner-message" class="bs-callout-info" style="display: none">
  error
</span>

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#banner-message {
  float: right;
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  font-size: 25px;
  text-align: center;
  transition: all 0.2s;
  margin: 0 auto;
  width: 300px;
}

button {
  background: #0084ff;
  border: none;
  border-radius: 5px;
  padding: 8px 14px;
  font-size: 15px;
  color: #fff;
}

#banner-message.alt {
  background: #0084ff;
  color: #fff;
  margin-top: 40px;
  width: 200px;
}

#banner-message.alt button {
  background: #fff;
  color: #000;
}

JavaScript

$(function() {
  $('#demo-form').parsley().on('field:validated', function() {
      var ok = $('.parsley-error').length === 0;
      $('.bs-callout-info').toggle(!ok);
    });
    
     $("#demo-form").on('submit', function(e){
        e.preventDefault();
        var form = $(this);

        form.parsley().validate();

        if (form.parsley().isValid()){
            alert('valid');
        }
    });
});