option tree show promotion box?

/*into theme-options.php*/
<?php

array(
'label'       => 'Show Boxed Promotion?',
'id'          => 'boxed_promotion',
'std'          => '',
'type'        => 'select',
'choices'     => array(
  array (
    'label'       => 'Yes',
    'value'       => 'yes'
  ),
  array (
    'label'       => 'No',
    'value'       => 'no'
  )
),
'section'     => 'homepage_item'
),

?>
/*into template-wecome.php*/
<?php

    $boxed_promotion = get_option_tree( 'boxed_promotion', '', false );
?>

<?php if($boxed_promotion == 'yes') : ?>
    <?php get_template_part('boxed-promotions'); ?>
<?php if($boxed_promotion == 'no') : ?>

<?php endif; ?>
<?php endif; ?>