<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<!------ Include the above in your HEAD tag ---------->
<div class="container">
<div class="row">
<div class="alert-group">
<div class="alert alert-success alert-dismissable">
<button type="button" class="close" data-dismiss="alert" aria-hidden="true">×</button>
<strong>Well done!</strong> You successfully read this important alert message.
</div>
<div class="alert alert-info">
<strong>Heads up!</strong> This alert needs your attention, but it's not super important.
</div>
<div class="alert alert-warning alert-dismissable">
<button type="button" class="close" data-dismiss="alert" aria-hidden="true">×</button>
<strong>Warning!</strong> Better check yourself, you're not looking too good.
</div>
<div class="alert alert-danger alert-dismissable">
<button type="button" class="close" data-dismiss="alert" aria-hidden="true">×</button>
<strong>Oh snap!</strong> Change a few things up and try submitting again.
</div>
</div>
</div>
</div>
