[TYPO3] hide div for unused "Content Elements"?

[Asbjørn Morell]

Hi.

I have mapped 3 columns with Templavoila. How do I hide/remove the div/class 
if it is empty? I have created a black border on my right, middle and left 
content areas (div). And I don't want to display that border if the content 
area is unused.

Regards.
Asbjørn Morell.