Adding a 1000x300 banner trough "advertising"

[DaVitsche]

I've tried adding a 1000x300 banner in the field "header 2" or "below navbar" trough the admin panel. But it overlaps with other fields (chatbox, login, forum etc.)

What do I have to fix this?

If more info is required, don't hesitate!

[LifesGreatestGift]

add css clear: both; to the element and maybe some padding.