this is it i think
<style type="text/css">
body{
background-position:top center;margin-top: 600;}
div.topbanner {
top: 0;
left: 49%;
margin-left: -500px;
width: 100%;
height: 720px;
position: absolute;
}
</style>
<div class="topbanner">
<a href="http://www.layoutcodes.net">
<IMG SRC="http://i95.photobucket.com/albums/l144/sonnyyola/BACKFLYER.jpg" border="0"></a></div><br>
depending on the size of it change the numbers in red. and the blue is the photo link