Why is it that what feels like it should be the most simple of tasks to me is always the most perplexing… Its in the title… but I have played for yonks but cant get it to work for me!
Essentially (just to make it even more plain I am hoping to get the following) (the image is the div background).

so whatever the size of the browser window the div is always centralised!
Thank you for any advice you can give… [=
edit: Basically what I am trying to achieve is a cheating way of having a popout window for a registration form.
so at the moment the entire page consists of the following:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta name="description" content="" />
<meta name="keywords" content="" />
<title>BlurbeRella - Registeration</title>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<link href="http://fonts.googleapis.com/css?family=Oswald" rel="stylesheet" type="text/css" />
<link rel="stylesheet" type="text/css" href="style.css" />
</head>
<div id="registerpage">
<img src="images/registerpage.png" class="registerpage" />
</div>
</html>
CSS:
img.registerpage{
text-align: center;
top: 100%;
}
#registerpage{
text-align: center;
width: 100%;
}
the css is my feeble attempt to keep it central…..
basically: the site at the moment (with no functionality yet) is blurberella.x10.mx
when the user clicks on register I will have the background image of the site itself so it looks like you are still on the same page.. then in the middle I will have my form… but to make sure that the site image still looks like a website I need it to remain central whatever the browser size!
I hope this makes sense… I no that I am cheating at this but with my current knowledge this is the best I can pull off…. I am still learning!
Maybe I misunderstood the question somewhere, but from my understanding you are looking for something like this.
HTML:
CSS: