Banner "Sold" on the classipress theme

Hello,

I have a site http://www.rcsalg.no and would love to have a “sold” banner on the ads that is marked “Sold”

I have done so it stands sold when you go in to an ad, but not on the frontpage..

Ad sold: http://rcsalg.no/ads/6s-4000-5500-mah-batteri-kjopes/
What i need is this: http://runninghorses.net/ See on the frontpage where an ad is sold.

How can i do this? I know i need a php code and some CSS..

Can somebody help me?

Best regards
Andre