Hiding Empty Custom Fields

Hi Guys,
Just hoping someone might have an answer to this one.
I’ve added my custom fields, and assigned a particular one to a more expensive package. The problem I’m having is that I’m using a tabbed layout on my single listing page, and the tab for this custom field still shows even when there’s no data in that field (i.e when that listing is on the cheap package).
I’ve seen a couple of examples of where the tab disappears when there’s no data, but don’t know how to do it with a custom field.
Thanks in advance guy!