title: How to set 'auto' height in JQuery animate
body: <p>Problem:
  I've a box(div) with fixed width but unknown (auto) height.</p>
  
  <p>I need to open/close that box using JQuery animate function.</p>
  
  <p>Problem is (commented in code too) on Open event, I need to set auto height, which I'm not able to do. Can someone please help set height to auto?</p>
  
  <p>JSFiddle: <a href="http://jsfiddle.net/7m5Qa/" rel="nofollow">http://jsfiddle.net/7m5Qa/</a>
  Code also given below:</p>
  
  <p><strong>HTML</strong></p>
  
  <pre><code>&lt;button id="open"&gt;open&lt;/button&gt;
  &lt;button id="close"&gt;close&lt;/button&gt;
  &lt;div id="textselector-body"&gt;
      a&lt;br/&gt;
      b&lt;br/&gt;
      c&lt;br/&gt;
  &lt;/div&gt;​
  </code></pre>
  
  <p><strong>Java Script</strong></p>
  
  <pre><code>$(document).ready(function(){
      $("#open").click(function(){
          $("#textselector-body").animate({
              height:'100px' //here is problem. I need it 'auto'.
          },2000);
      });
      $("#close").click(function(){
          $("#textselector-body").animate({
              height:'0'
          },2000);
      });
  });​
  </code></pre>