full width submenu

I've followed the tutorial for the full width submenu, but from what I realise, full width = full width of the menu. In my case I get something like that:


What I want to do is get the full width of the screen (browser). This:


The only way I managed to do it, is by changing div#maximenuck li.fullwidth > div.floatck to position: fixed;

It works, but of course when you scroll down and the submenu is open, it stays there, instead of scrolling up along with the rest of the menu.
Is there a way to do it?

Hi
right, by default it takes the width of the menu, this is what happened in your case
give me your url to check this, and removed the position:fixed to the div.floatck
CEd

the url is postcereals.co.uk
I have to send you the username and password because the site is locked at the moment
should I email it to you? I don't see a private message option

write me here
www.joomlack.fr/contact
and put the link of this page in your message

add this in your css

it works but it has the same effect as putting div#maximenuck li.fullwidth > div.floatck to position: fixed;

If you scroll down while having the submenu open, it stays there and it doesn't scroll up with the rest of the menu.

I think simple css might not be able to do this. Is it possible to have the div floatck, open outside the main menu's ul?