Centered pop up issue

Hey guys, thanks heaps for your help earlier with the border thing, appreciated.

Now im trying to get a centered pop up to work, heres my script currently;

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<title>Shudder Productions</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">

<style type="text/css">
body {
margin-left: 0px;
margin-top: 0px;
margin-right: 0px;
margin-bottom: 0px;
<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" codebase=",0,29,0" width="768" height="576">
  <param name="movie" value="">
  <param name="quality" value="high">
  <embed src="" quality="high" pluginspage="" type="application/x-shockwave-flash" width="768" height="576"></embed></object>


Ive been looking around on tutorials for this but im a little confused, can anyone point me in the right direction?

Cheers :mario: