title: change every 2 rows instead of every table row
body: <p>I have this code for changing the class from odd to even for every row. What i would like it to do is go even even odd odd instead of even odd even odd:</p>
  
  <pre><code>window.addEvent('domready', function() {
  
  var count = 0;
  
  $$('table.pretty-table tr').each(function(el) {
  
  el.addClass(count++ % 2 == 0 ? 'odd' : 'even');
  
  });
  
  });
  </code></pre>