Clickable background ads in wordpress theme?

I'm modifying a wordpress them开发者_JS百科e, but I can't really figure out how I can make each part( left, right, top) of the background clickable and add some ad banners there.

Could anyone help me achieve this?

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The simplest solution would be to place each ad in div. In most cases this ads point to some external sites(the ads are links so they're clickable).