title: How to change split sign from html element with jQuery
body: <p>I have some <code>h3</code> element:</p>
  
  <pre><code>&lt;h3&gt;Data Performance&lt;/h3&gt;
  </code></pre>
  
  <p>I need to change it to class name: <code>data_performance</code>. 
  So i do this but something is wrong, can anybody tell me what?</p>
  
  <pre><code>var $product_name = $('.subpage_promo.top').find('h3').text().toLowerCase(),
      $product_name_mod = $product_name.split(' ').replace('_');
  </code></pre>
  
  <p>Thx for help.</p>