Custom Field Bookmarks

Hi, I’ve created a template which pulls in link categories, instead of hard coding this I’m hoping that the user can enter a link category id within a custom field and it will display the correct list, avoiding creating multiple templates.

The code I have is,

<?php $field = get_post_meta( $post->ID, ‘link-category’, true ); ?>
<?php if( $field && ” != $field ) : ?>
<h2>Additional Reading</h2>
<?php wp_list_bookmarks(array(‘title_li’=>__(”),’category’=>’9’)); ?>
<?php endif; ?>

Instead of hard coding the ID which is 9, I want to replace it with the custom field value which is found under $field, I was wondering how I can insert the $field value in place of the 9.

If anyone has any ideas it would be good to hear from you, cheers