title: Using data attributes with jQuery
body: <p>I have this button:</p>
  
  <pre><code>&lt;button type="button" class="themeChanger" data-themeValue="grid" value="Grid"&gt;
     &lt;img src="templateImages/Icon_200.png" /&gt;                
  &lt;/button&gt;
  </code></pre>
  
  <p>And this jQuery:</p>
  
  <pre><code>$(".themeChanger").click(function () { 
      alert($(this).attr("data-themeValue")); 
      alert($(this).data("themeValue")); 
  });
  </code></pre>
  
  <p>For some reason the first alert shows "grid" like it should, but the second shows undefined.  Is there something stupid I'm missing?</p>