检测youtube视频何时结束-javascript-不工作

我有数据库中的youtube视频（只有它们的URL）。它们的格式如下：

现在，我想检测视频何时结束，并在视频容器中显示其他内容

我尝试了以下步骤：

1. changed the above youtube url to: 

但我既没有收到

“api准备就绪！”

也没有收到

“完成”

警报。。我做错了什么

这很容易：

    var tag = document.createElement('script');
    tag.src = "https://www.youtube.com/iframe_api";
    var firstScriptTag = document.getElementsByTagName('script')[0];
    firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);

    var player;
    function onYouTubeIframeAPIReady() {
        player = new YT.Player('myyoutubevideo_iframe_div', {
            height: '410',
            width: '100%',
            videoId: '{{ video.yt_id }}',
            events: {
                'onReady': onPlayerReady,
                'onStateChange': onPlayerStateChange
            }
        });
    }
    function onPlayerReady(event) {
        event.target.playVideo();
    }
    var done = false;
    function onPlayerStateChange(event) {
        if (event.data == YT.PlayerState.ENDED) {
            $('#myyoutubevideo_iframe_div').hide();
            $('#aftervideo_div').show();
        }
    }

    var tag = document.createElement('script');
    tag.src = "https://www.youtube.com/iframe_api";
    var firstScriptTag = document.getElementsByTagName('script')[0];
    firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);

    var player;
    function onYouTubeIframeAPIReady() {
        player = new YT.Player('myyoutubevideo_iframe_div', {
            height: '410',
            width: '100%',
            videoId: '{{ video.yt_id }}',
            events: {
                'onReady': onPlayerReady,
                'onStateChange': onPlayerStateChange
            }
        });
    }
    function onPlayerReady(event) {
        event.target.playVideo();
    }
    var done = false;
    function onPlayerStateChange(event) {
        if (event.data == YT.PlayerState.ENDED) {
            $('#myyoutubevideo_iframe_div').hide();
            $('#aftervideo_div').show();
        }
    }