title: html5-video by button $(...).play is not a function
body: <p>I try to play videos one after the other via button or automatically at the end of the video.
  by this code:</p>
  
  <pre><code>//automatically play
  $("#videoPlayer").bind('ended', function() {
  if(cnt &lt;= 10 &amp;&amp; bNum == 0) cnt++;
  $('#videoPlayer').attr('poster','./media/spot'+cnt+'.jpg').html('&lt;source src="./media/spot'+cnt+'.mp4" type="video/mp4"&gt;&lt;source src="./media/spot'+cnt+'.ogg" type="video/ogg"&gt;&lt;source src="./media/spot'+cnt+'.webm" type="video/webm"&gt;');
  $('#video-title').html('Spot '+cnt);
  if(cnt &lt; 10) {
    this.load();
    this.play();
    cnt++;
  }
  bNum = 1;
  if(cnt &gt;= 10) $('.link1').remove();
  });
  
  //Play by the button
  $('.link1').on('click', function() {
    if(cnt &lt; 10 &amp;&amp; bNum == 0) cnt++;
    $(this).attr('rel', cnt).attr('title', 'Spot '+cnt);
    $('#videoPlayer').attr('poster','./media/spot'+cnt+'.jpg').html('&lt;source src="./media/spot'+cnt+'.mp4" type="video/mp4"&gt;&lt;source src="./media/spot'+cnt+'.ogg" type="video/ogg"&gt;&lt;source src="./media/spot'+cnt+'.webm" type="video/webm"&gt;');
    $('#video-title').html('Spot '+cnt);
    if(cnt &gt;= 10) $('.link1').remove();
    if(cnt &lt;= 10) {
      if($('#videoPlayer').load()) $('#videoPlayer').play();
      cnt++;
    }
  });
  </code></pre>
  
  <p>the html part is:</p>
  
  <pre><code>&lt;video width="640" id="videoPlayer" autoplay preload="metadata" poster="./media/spot1.jpg"&gt;
  &lt;source src="./media/spot1.ogg" type="video/ogg"&gt;
  &lt;source src="./media/spot1.mp4" type="video/mp4"&gt;
  &lt;source src="./media/spot1.webm" type="video/webm"&gt;
  Your browser does not support the video tag.
  &lt;/video&gt;&lt;/div&gt;
  &lt;ul&gt;
  &lt;li class="link1" rel="2"&gt;Nächster Spot &lt;/li&gt;
  &lt;/ul&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>the automatic part works well without an error. But the part by button gets an error at the line;</p>
  
  <pre><code>$('#videoPlayer').play(); 
  </code></pre>
  
  <p>with the message </p>
  
  <pre><code>"$(...).play is not a function". 
  </code></pre>
  
  <p>I can't find why. (For <code>this.play()</code> I can also write <code>$('videoPlayer')</code> in the automatic part. It is the same.)</p>