Simplest solution is to make your page fixed width and put it all inside a #wrap div:-
CSS
Code:
#wrap { position: relative. width: ???px; margin: 0 auto; }
HTML markup:-
Code:
doctype here
<html>
<head>
Head section
</head>
<body>
<div id="wrap">
All page html here
</div>
</body>
</html>
Remember to include a doctype as the first item of your HTML page code from here:-
http://www.w3.org/QA/2002/04/valid-dtd-list.html
The #wrap div width should be the total widths of all you divs in the same line plus all their side margins, side padding and side borders.
Code downloaded to my PC will be deleted in due course.
WIN7; IE9, Firefox, Opera, Chrome and Safari for Windows; screen resolution usually 1366*768.
Also IE6 on W98 with 800*600 and IE8 on Vista 1440*900.