将弹出窗口/灯箱应用于iframe

Question

我有这个脚本从JSON中获取东西。点击缩略图，它旁边会打开iframe。好吧，我想让iframe弹出并使背景更暗（你知道演练）。我怎么能这样做？

    $(function() {
    var i=0;
    var twitchApi = "https://api.twitch.tv/kraken/streams";
    var twitchData;
    $.getJSON(twitchApi, function(json) {
        twitchData = json.streams;

        setData()
    });

    function setData(){
        var j = twitchData.length > (i + 9)  ? (i + 9) : twitchData.length;
        for (; i < j; i++) {
            var streamGame = twitchData[i].game;
            var streamThumb = twitchData[i].preview.medium;
            var streamVideo = twitchData[i].channel.name;
            var img = $('<img style="width: 250px; height: 250px;" src="' + streamThumb + '"/>')
            $('#twitch').append(img);
            img.click(function(){
            $('#twitch iframe').remove()
            $('#twitchframe').append( '<iframe frameborder="0" style="overflow:hidden; margin-left: 25px; width:400px; height:250px; position: fixed; top: 0; margin-top: 23.55%;" src="http://player.twitch.tv/?channel=' + streamVideo + '"></iframe>');
          });
        }
    }       

    $('#load').click(function() {
        setData();
    }); 
});