<?php global $wpalchemy_ma_header_image; ?>
<div class="my_meta_control metabox">

				<p><em>If a header image is specified here, it will override the default header image specified in Appearance-Header.  It will be displayed for this post or page only.  Header images should be at least 1000 pixels wide.  A header image will not be displayed for small screens.</em></p>
  
    <?php $mb->the_field('imgurl'); ?>
    <?php $wpalchemy_ma_header_image->setGroupName('nn')->setInsertButtonLabel('Insert'); ?>
 
    <p>
        <?php echo $wpalchemy_ma_header_image->getField(array('name' => $mb->get_the_name(), 'value' => $mb->get_the_value())); ?>
        <?php echo $wpalchemy_ma_header_image->getButton(); ?>
    </p>
 
 
</div>