Konkurrence Regler

Quick Question (No problem if you reply in DK - I just cant write in Danish!)

I want to run a banner ad to get traffic on my website. I think a konkurrence could be a good idea to get people to click in - register to win an ipod or dinner for two - something in that style...

 I'm wondering if anyone can point me to information about the legal requirements of running this type of konkurrence. Any help would be appreciated. Thanks!

 Ongo