关于视频播放问题？按照js高级程序设计指南上508页写的，但不知道哪错了？

Question

<div class="media">

        <div class="video">

            <video id="player" src="../1.mkv" poster="../images/poster.jpg" width="600" height="446"></video>

        </div>

        <div class="controls">

            <input type="button" value="Play" id="video-btn">

            <span id="curtime">0</span><span id="duration">0</span>

        </div>

    </div>

    <script>

        var player=document.getElementById("player");

        var btn=document.getElementById("video-btn");

        var curtime=document.getElementById("curtime");

        var duration=document.getElementById("duration");

        duration.innerHTML=player.duration;

        btn.onClick=function(event){

            if(btn.paused){

                player.play();

                btn.value="Pause";

            }else{

                player.pause();

                btn.value="Play";

            }

        };

        setInterval(function(){

            curtime.innerHTML=player.currentTime;

        },250);

    </script>

Answer 1

btn.onclick=function(event){&nbsp; if(player.paused){