title: Disable radio buttons based on value
body: <p>I want to disable radio buttons based on the value of a variable. The radio that is equal to the variable value should be disabled.</p>
  
  <p>Ex:</p>
  
  <pre><code>&lt;input type="radio" name="r1" value="a" /&gt;Value a
  &lt;input type="radio" name="r1" value="b" /&gt;Value b
  </code></pre>
  
  <p>So if the <code>$variable = 'a';</code> then the radio button which has the value <code>a</code> should be disabled.</p>