title: <g:checkBox> click calling a controller function
body: <p>When the user clicks on the checkbox, I want to call a controller function and pass the current status of checkbox, whether it's checked or not.</p>
  
  <p>I know how to do this using jQuery but I want to do this from the checkBox itself.</p>
  
  <pre><code>&lt;g:checkBox id="customer_checkbox" name="customer_checkbox" value="${checked}" /&gt;
  </code></pre>
  
  <p>Controller function to be called:</p>
  
  <pre><code>class updateController {
     def updateIndex () {
        // do something
     }
  }
  </code></pre>