Need an additional Admin column to show conditionally

[Dirty Butter]

I've added a customer_notes column to the _customers table, and I have added the appropriate column in customers.index.php.
 
The code below does work, but I would much prefer that the Notes link ONLY SHOW for those customers who actually HAVE something in Notes.
 
What do I need to add, so that the Notes link only shows if customer_notes is NOT NULL?
 

<td align="center">
			<a href="{$customer.edit}" title="{$LANG.common.edit}"><img src="{$SKIN_VARS.admin_folder}/skins/{$SKIN_VARS.skin_folder}/images/edit.png" alt="{$LANG.common.edit}" /></a>
			<a href="{$customer.delete}" class="delete" title="{$LANG.notification.confirm_delete}"><img src="{$SKIN_VARS.admin_folder}/skins/{$SKIN_VARS.skin_folder}/images/delete.png" alt="{$LANG.common.delete}" /></a>
		  </td>
<td><a href="{$STORE_URL}/admin.php?_g=customers&sort%5Bregistered%5D=DESC&action=edit&customer_id={$customer.customer_id}#customer_notes">Notes</a></td>

[bsmither]

{if !empty($customer.customer_notes)}
<a href="{$STORE_URL}/admin.php?_g=customers&sort%5Bregistered%5D=DESC&action=edit&customer_id={$customer.customer_id}#customer_notes">Notes</a>
{/if}

[Dirty Butter]

So !empty means not empty? Good to know. Thanks! That gives me an easy way to note when I've contacted a person who registered, but has not purchased anything, or had problems ordering.