<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/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 ---------->
<html lang="en">
<body>
<h2>Guess</h2>
<button onclick="flipCoin('heads')">Heads</button>
<button onclick="flipCoin('tails')">Tails</button>
<p id="result-text"></p>
</body>
</html>
