title: Move focus to a particular field
body: <p>I have a button that will add show a form on the page. how can I move the focus to the first field of the form when that button is clicked?</p>
  
  <p>simple example:</p>
  
  <p>HTML:</p>
  
  <pre><code>&lt;form style="display:none;" id="newForm"&gt;
     &lt;input type="text" id="firstField"&gt;
  &lt;/form&gt;
  &lt;input type="button" id="showForm" value="add new"&gt;
  </code></pre>
  
  <p>jQuery:</p>
  
  <pre><code> $("#showForm").click(function(){
       $("#newForm").show();
       //move focus??
  });
  </code></pre>