title: jQuery readonly attribute problems
body: <p>I have this</p>
  
  <pre><code>&lt;input type="text" id="tbox" name="tbox" readonly="readonly" /&gt;
  </code></pre>
  
  <p>I have a button on which I do this</p>
  
  <pre><code>$('#tbox').removeAttr('readonly');
  </code></pre>
  
  <p>I've also tried doing this</p>
  
  <pre><code>$('#tbox').attr('readonly', false);
  </code></pre>
  
  <p>.. but none work..</p>