[Typo3] tmenu_layers question

[Pierre]

Hi list,

I'm trying to configure a tmenu_layers..all works fine but i wanna know if 
there's a way to keep the hover effect on the first level when navigate 
through the 2nd level menu. I'm not sure to be very clear so ...
http://chaillet.dyndns.org/home/chaillet/www/ethemis/t37d/index.php?id=1
this my tmenu when you are on the first level (menu top) the case is white 
surronded but i want when you navigate into the second level to keep the 
surronded border etc...
So i just wanna know if it's possible via typo3 and some clues to configure 
this ... thanks a lot for ny informations