title: hide myclass for which div is not available
body: <p>I have for eg <code>#test</code> on many page and in some page the <code>#test</code> div is not so I wanted to hide <code>.myclass</code> in which <code>#test</code> div is not. So I tried the following:</p>
  
  <pre><code>var $bs = $('body').find('#test');
      if($bs === 'undefined'){ // but this seems wrong also tried type of $bs === 'undefined'
  
          $('.myclass').css('display','none');
      }
  </code></pre>