title: align two divs, one at top one at bottom of a third div
body: <p>I have this code:</p>
  
  <pre><code>&lt;div id="container"&gt;
      &lt;div id="1"&gt; div 1&lt;/div&gt;
      &lt;div id="2"&gt; div 2&lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I want to put <code>div 1</code> at the top, and <code>div 2</code> at the bottom of <code>container</code>, no matter how much the height of <code>container</code> is . How can I do so? </p>