<html>
<head>
<script src="https://libs.baidu.com/jquery/1.10.2/jquery.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>