title: Javascript only affects one element
body: <p><em>I don't understand, the border is only visible on the first item, why?</em></p>
  
  <p><strong>HTML</strong></p>
  
  <pre><code>&lt;div id="theContainer"&gt;
      &lt;div id="item"&gt;Content 1&lt;/div&gt;
      &lt;div id="item"&gt;Content 2&lt;/div&gt;
  &lt;/div&gt;​
  </code></pre>
  
  <p><strong>JavaScript</strong></p>
  
  <pre><code>document.getElementById('item').style.borderTop = '1px solid #0ea2c7';​
  </code></pre>
  
  <p>JsFiddle: <a href="http://jsfiddle.net/SbNKa/52/" rel="nofollow">here</a></p>