Raspberry Pi Light Switch UI

<!DOCTYPE html>
<html>
    <head>
        <title>My First Light Switch</title>
        <script>
            function lights(onoff) {
                var oReq = new XMLHttpRequest();
                oReq.open("GET", "/lights.php?" + onoff);
                oReq.send();
            }
        </script>
    </head>

    <body>
        <button onclick="lights('on')">Turn on the lights</button>
        <button onclick="lights('off')">Turn off the lights</button>
    </body>
</html>