list.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
</head>
<body>

    <form>
        <input type="text" id="selection">
        <button name="Add" id="push">Add</button>
        <button name="Remove" id="pop">Remove</button>
        <button name="View" id="view">View</button>
    </form>

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