title: Set radio button 'checked' in jquery based on ID
body: <p>I have two radio buttons with the same name, one is checked by default.  How can you check or uncheck a radio button in jQuery when selecting from id?</p>
  
  <p>I've tried:</p>
  
  <pre><code>$('#radio1').attr('checked','checked');
  $('#radio1').attr('checked', true);
  </code></pre>
  
  <p>Nothing seems to work.. any ideas?</p>
  
  <p>Thank you!</p>