Z index for Drop down menu not working?

I've just been playing with a drop down menu I got from here:

http://javascript-array.com/scripts/simple_drop_down_menu/

It looks great apart from the fact that when I upload it the z index isnt working and the drop downs sit under all of the content. Locally it looks fine. I've used exactly the same code as is used on the example...literally just copied and pasted it and then just changed the colours....

Any suggestions anyone??

Thanks very much

Rach

 

Nobody?

Heres where I've uploaded it if that helps?

http://penair.com.au/index2.html

Thanks

 

Just realised I should prob have put this in the CSS section...I'll copy it into there now...if a mod sees this could you please delete it