Layout box from end to end of the screen

Question

The caprice is simple: I want to create 100px tall line (vertical gradient) from end to end of the screen at the top of it, independently of screen's size.
I have already set up the header which is 80px tall and appears 5px from the top (so there is a space where background gradient should continue to appear). The sites main content (header included) is 930px wide-positioned at the center (once again - so the background gradient should appear at the both sides of main content field (crossing the wraper) and at scattered instances - at the gaps too.)
I understand how to create gradient itself (1 pixel wide jpg or png which repeats over and over), but how and where to define layout box for current needs?
Any suggestions?

Answer 1

If you look at my website, there are several gradient background images used on the page that flow from top gradient to bottom solid color fills.
http://alt-web.com/
CSS:
body {background: #E6E6E6 url (some-image.jpg) repeat-x}
#content {
background: #F0F0F0 url (some-other-image.jpg) repeat-x;
margin: 0 auto;
width: 970px;
border: 2px solid #FFF;
Nancy O.
Alt-Web Design & Publishing
Web | Graphics | Print | Media  Specialists
www.alt-web.com/
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