<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="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script> <!------ Include the above in your HEAD tag ----------> <div class="container"> <div class="row"> <div class="alert alert-success"> <strong>Success!</strong> Indicates a successful or positive action. </div> <div class="alert alert-info"> <strong>Info!</strong> Indicates a neutral informative change or action. </div> <div class="alert alert-warning"> <strong>Warning!</strong> Indicates a warning that might need attention. </div> <div class="alert alert-danger"> <strong>Danger!</strong> Indicates a dangerous or potentially negative action. </div> </div> </div>