Hiding labels on author page for empty fields

Hi,

I am building a custom author.php page to include some additional fields that I have provided to my users. One field that I provide them with is for their AIM ID. So, to add that to the author page I have included

AIM: <?php echo $curauth->aim; ?>

The problem, however, is that AIM: is displayed on the author page even if the user didn’t enter an AIM ID. Can someone please tell me how I could wrap that in an if clause so that the AIM label would only appear if $curauth->aim; isn’t empty?