A drop-in piece of Javascript that will take an array of YouTube video IDs and embed them on the page

youtubeloop.js

<script>
    // Replace line below with video id(s)
    // e.g. ["K0FdCdQItDI"]; or ["K0FdCdQItDI","8B3dpnUcMBY"];
    //
    //
    var ids = ["K0FdCdQItDI"];
    //
    //
    // Don't edit below
    if (ids.length == 1) {
        document.write("<iframe width=\"640px\" height=\"360px\" src=\"https://www.youtube.com/embed/" + ids + "?modestbranding=1&rel=0&autoplay=1\" frameborder=\"0\" allowfullscreen></iframe>");
        document.write("<br />");
        }
    else {
        for (var i = 0; i < ids.length; i++) {
            document.write("<iframe width=\"640px\" height=\"360px\" src=\"https://www.youtube.com/embed/" + ids[i] + "?modestbranding=1&rel=0\" frameborder=\"0\" allowfullscreen></iframe>");
            document.write("<br /> <br />");
        };
    };
</script>