Positioning tabs within a relative container

[VaporAction]

I'm trying to make a site that has a centered page with centered navigation tabs at the top very similiar to...
http://www.apple.com

the part that is messing me up is the background image behind the tabs...

I can't seem to get the tabs to overlap the background image without using position: absolute...

if I use position absolute then the tabs don't stay in the right position with my relatively positioned page...

here's a diagram (just for example, not real html)

<div container position: relative; margin: auto;>
<div tabs background>
<div navigation tabs>
</div>