Changing data-url or similar attributes on Element
<p>I'm trying to access the data-url attribute of the following element so it could be replaced upon callback or as needed with jQuery / Javascript. </p>

<p><strong>What method will work to do this?</strong></p>

<pre><code>&lt;a id="twitter_link" href="https://twitter.com/share" class="twitter-share-button" data-via="imdto" data-lang="en" data-url="http://mydomain.com/changeme"&gt;Tweet&lt;/a&gt;
</code></pre>

<p>I've tried using <code>attr()</code>, <code>prop()</code> functions but returns undefined.</p>
