title: React onClick not firing
body: <p>The following code doesn't work. The <code>onClick</code> events are never fired but I see no errors in browserify or console.</p>
  <pre><code>var React = require('react');
  
  var Button = React.createClass({
    render: function() {
      return (
        &lt;div className=&quot;Button&quot;&gt;
          &lt;span className=&quot;left&quot; onclick={function() {alert(&quot;left&quot;)}}&gt;Left&lt;/span&gt;
          &lt;span className=&quot;right&quot; onclick={function() {alert(&quot;right&quot;)}}&gt;Right&lt;/span&gt;
          &lt;span className=&quot;middle&quot; onclick={function() {alert(&quot;middle&quot;)}}&gt;Middle&lt;/span&gt;
        &lt;/div&gt;
      );
    }
  });
  
  module.exports=Button;
  </code></pre>
  <p>I use alert just for testing small CSS. Why isn't onclick firing?</p>