How to get video src attribute
<p>I need to get the src attribute of a video tag, but something is wrong:</p>

<pre><code>&lt;video id="vdisk" controls poster="placeh/02.jpg"&gt;
    &lt;source src="placeh/01.mp4" type="video/mp4"&gt;
&lt;/video&gt;
</code></pre>

<h3>JavaScript</h3>

<pre><code>var a = $("#vdisk").attr("src");
console.log(a); // undefined
</code></pre>