title: Click checkbox only if already checked
body: <p>I want to click on a checkbox only if it is already checked.</p>
  
  <p>The following code doesn't seem to work:</p>
  
  <pre><code>if(this.test.assert(this.evaluate(function () {return document.getElementById('myID').checked;}))) 
  {           
      this.click('#myID');     
  }
  </code></pre>
  
  <p>What's the correct syntax?</p>