[jQuery] Superfish - vs. 1.4.8 - cannot force background color to span across FULL PAGE

[KellyS]

I desperately (always need to) span any menu across the full page. I'm
shocked there are no examples of this.  Anyway, it doesn't work.  See
example code below.  I need to define a css class so that the menu
spans the FULL width of the page.
Any workarounds or do I scrap jQuery??


css:
#menuback {
        background-color: #BDD2FF;
        padding: 0px; margin-left:0px; margin-right: 0px; width:100%;
}

html code:
<div id="menuback">
                <ul class="sf-menu">
                        <li class="current">
                                <a href="#a">menu item &#8595;</a>
                                <ul>
                                        <li>
                                                <a href="#aa">menu item that is 
quite long</a>
                                        </li>
                                </ul>
                        </li>
                </ul>
</div>