title: CSS Dynamic Heights
body: <p>I have three div tags, a wrapper and two side by side within the wrapper:</p>
  
  <pre><code>&lt;div id="wrapper"&gt;
     &lt;div id="left"&gt;&lt;/div&gt;
     &lt;div id="right"&gt;&lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I want to create the condition where the <code>&lt;div id="left"&gt;</code> tag is variable height, stretching the wrapper.</p>
  
  <p>As a result, the <code>&lt;div id="right"&gt;</code> will expand to whatever height the wrapper has become.</p>
  
  <p>What CSS will accomplish this? Thanks!</p>