title: Radio input checked
body: <p>I have 2 radio inputs. A,B</p>
  
  <p>I an trying to make A as a selected radio by default.
  And I want the following behavior: when A get hidden then B should get checked by default.</p>
  
  <p>This is what I tried. Please take a look.</p>
  
  <pre><code>&lt;div &gt;
       &lt;input type="radio" checked="checked" value="0" name="a" /&gt;
       &lt;strong&gt;A&lt;/strong&gt;
  &lt;/div&gt;
  &lt;div&gt;
       &lt;input type="radio" checked=""  value="1" name="b" /&gt;
       &lt;strong&gt;
       B
      &lt;/strong&gt;
  &lt;/div&gt;
  &lt;input type="text" onfocus="Javascript:document.forms[1].opt_payment[1].checked=true;" maxlength="20" value=" " name="" /&gt;
  </code></pre>
  
  <p>Thanks</p>