title: How to put a div at center of another div?
body: <p>I'd like to have one div at center of another div horizontally.</p>
  
  <pre><code>    &lt;div id="container"&gt;
          &lt;div id="centered"&gt;
              hello world;
          &lt;/div&gt;
      &lt;/div
  </code></pre>
  
  <p>I tried with below style with "margin: 0px auto" trick, but it only works in FF, not in IE.</p>
  
  <pre><code>    div
      {
          border-width: 2px;
          border-style: solid;
      }
      #centered
      {
          margin: 0 auto;
          width: 30px;
      }
      #container
      {
          width: 100px;
          }
  </code></pre>
  
  <p>Is there any way to achieve this cross browser?</p>