ping.html

<head>
    <script src="./ping.js"></script>
    <script>
    var do_ping = function() {
        ping(document.getElementById('pingurl').value).then(function(delta) {
            alert(delta);
        }).catch(function(error) {
            alert(String(error));
        });
    };
    </script>
</head>
<body>
    <input id='pingurl' type='text' value='http://google.com'></input>
    <button onclick='do_ping()'>Ping</button>
</body>