title: Jquery attr method returns undefined for a checked checkbox
body: <p></p>
  
  <p>For the above checkbox</p>
  
  <pre><code>document.getElementById("checkbox1").checked // -&gt; returns true
  </code></pre>
  
  <p>But</p>
  
  <pre><code>var byAppr = document.getElementById('checkbox1').value;
  $(byAppr).attr('checked') // -&gt; returns undefined
  </code></pre>
  
  <p>I am testing this in firefox 3.6</p>