I have just realised a lot of people out there dont know how to do this so here is a quick and simple tutorial.
Put this in your CSS
body {
text-align: center;
}
#container {
margin: 0 auto;
width: 999px;
text-align: left;
}
And this in your page.
<body>
<div id="container">
...entire layout goes here...
</div>
</body>
Margin:0px auto specifies 0 pixel margins top and bottom and auto margins left and right, and for older IE browsers who dont support that the text alighn centre will take care of that, then tou specify text align left in the container to get the text aligned left again.
Simple.
