<!DOCTYPE html>
<html>
<head>
<script src="/lib/jquery-1.12.2.min.js"></script>
<script>
$(document).ready(function(){
$("button").click(function(){
$("p").add("<br><span>A new span element.</span>").appendTo("p");
});
});
</script>
</head>
<body>
<button>Add a span element</button>
<p>A p element.</p>
</body>
</html>