changing the table?

hey guys,

I've installed your poll this evening and it looks great!!! But it even looks better I'f someone can tell me how I can do this: I want to modify the table the poll is in, where it says "advanced poll" at the top I want to choose an background image instead but I can't find the code to fix this!!

So I will be very pleased if someone can tell me where to do this.............

greetz