Genesis - add odd/even post class

gistfile1.php

<?php

//* Add odd/even post class
function sample_oddeven_post_class ( $classes ) {
  global $current_class;
	$classes[] = $current_class;
	$current_class = ($current_class == 'odd') ? 'even' : 'odd';
	return $classes;
}
add_filter ( 'post_class' , 'sample_oddeven_post_class' );
global $current_class;
$current_class = 'odd';