MainCode

var fa=$("body");  
        var btn=$("<li></li>");  
        var json={  
            "background":"#31e16d",  
            "height":"16px",  
            "padding":"5px",  
            "cursor": "pointer",  
            "top":"300px",  
            "right":"80px",  
            "position": "fixed"  
        };  
        btn.css(json);  
        btn.html("<span id='lfsenior'>开启自动播放模式</span>");  
        fa.append(btn);  
        var bodywidth=$("#body").css("width");  
        var mainwidth=$("#main").css("width");  
        btn.click(function () {  
           $("#lfsenior").html("自动模式已开启");  
           //关闭弹题  
            setInterval(function(){  
            //开启倍速播放
            document.getElementsByClassName("speedTab15")[0].click();
                $(".popboxes_close").click();  
                //获取当前进度  
                var spans=$(".current_play span");  
                var progress=spans[spans.size()-1].innerHTML;  
                if("100"==progress.substring(progress.lastIndexOf("『")+1,progress.lastIndexOf("』")-1)){  
                   //播放完毕  
                   $(".next_lesson a").click();  
                }else{  
                   $("#vjs_mediaplayer_html5_api")[0].play();  
                    $("#vjs_mediaplayer_html5_api")[0].muted=true;  
                }  
                 $("#lfsenior").html("自动模式已开启,本章进度:"+progress+"%");  
            },100);  
  
  
        });  
        //开启自动模式
        document.getElementById("lfsenior").click();