trying to add a div to the very top of the page

i want some extra navigation so i want to add a div to the top of my site.

so, i created a class (i know the width is not the entire page length but its irrelevant here)

.topmost{
background-color: #B90101;
color: #FFFFFF;
width:340px;
height:107px;
}

I created an instance of the class just under header (it may not be live now). it is also above headerleft or headerright or navtop divs:

<div class="topmost">
sdafsadf
</div>

the problem is that it shifts some things vertically downward but not everything. i want it to shift everything down together in unison obviously.

how do i do this to yield the results i am looking for?

page is at

wrap HeaderLeft, HeaderRight, and clear in a div

essentially if you placed this nav above "header" it would work fine

wrap HeaderLeft, HeaderRight, and clear in a div

essentially if you placed this nav above "header" it would work fine

much appreciated.