[Plugin: Media Tags] Conditional Testing

Hi All

Maybe somebody can help me here?
I’ve been trying to do this for days now with no success.
I’m trying to use the “in_mediatag()” function to add a class, but just not getting it right. There don’t seem to be any examples on the site. I’d like to use it in a function that was shown at http://digwp.com/2009/08/awesome-image-attachment-recipes-for-wordpress/

This is what I’m trying:

if (in_mediatag('choice')){
echo ' my-choice-item';
}

In context:

function gallery_toolbox($size = thumbnail) {

	if($images = get_children(array(
    'order' => 'ASC',
		'orderby' => 'menu_order',
		'post_parent'    => get_the_ID(),
		'post_type'      => 'attachment',
		'numberposts'    => -1, // display the amount to show per post
		'post_status'    => null,
		'post_mime_type' => 'image',
	))) {
		foreach($images as $image) {
			$attimg   = wp_get_attachment_image($image->ID,$size);
			$atturl   = wp_get_attachment_url($image->ID);
			$attlink  = get_attachment_link($image->ID);
			$atttitle = apply_filters('the_title',$image->post_title);
			$postlink = get_permalink($image->post_parent);
			$posttitle= get_the_title($image->post_parent);

			echo '<dl class="gallery-item';
			if (in_mediatag('choice')){
			echo ' my-choice-item';
			}
			echo '"><dt class="gallery-icon"><a href='.$attlink.' >'.$attimg.'</a></dt><dd class="gallery-caption"><a href='.$attlink.'>'.$atttitle.'</a></dd></dl>';

		}
	}
}

http://wordpress.org/extend/plugins/media-tags/