I think this may help:
<div id="header">
<div class"wrap"> -- Content -- </div>
</div>
<div id="main">
--content--
</div>
<div id="footer">
<div class"wrap"> -- Content -- </div>
</div>
That can be the basic HTML .
Then:
#header{
background:url(header-bg.jpg) repeat-x;
}
#footer{
background:url(footer-bg.jpg) repeat-x;
}
.wrap{
width:960px;
}
This will work if I’ve understood your problem correctly =)

