Untitled

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="ejemploXHR.css">
    <title>Document</title>
</head>
<body>
    <section id="control-center">

        <button id="get-btn">GET Data</button>
        <button id="post-btn">POST Data</button>
    </section>

    <script src="ejemploXHR.js"></script>
</body>
</html>