Sentralizar web atraves del style.css

Hola a todos, y muy buen dia.
Estoy creando una pagina, es el famoso script del millon de pixel.
cuando visualizo la pagina desde un monitor de un tamaño normal, la pagina se ve todo bien, pero cuando la abro desde un monitor mas grande la pagina aparese en la parte izquierda, osea que no esta centralizada....
la pagina esta echa en php y mysql..

aqui les dejo el codigo del estilo (style.css), espero que me puedan ayudar a centralizar la pagina, no se mucho de programacion.

BODY {
PADDING-RIGHT: 0px; PADDING-LEFT: 0px; FONT-SIZE: 9pt; BACKGROUND: url(bodybg.gif) #999999; PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-TOP: 0px; FONT-FAMILY: trebuchet ms, helvetica, verdana
}
TD {
FONT-SIZE: 9pt; COLOR: #000000; FONT-FAMILY: trebuchet ms, helvetica, verdana
}
#pageads {
MARGIN-LEFT: auto; VERTICAL-ALIGN: top; MARGIN-RIGHT: auto; PADDING-TOP: 10px; TEXT-ALIGN: center
}
#pixels {
BORDER-RIGHT: 0px; BORDER-TOP: 0px; LEFT: 0px; MARGIN-LEFT: auto; BORDER-LEFT: 0px; WIDTH: 1000px; MARGIN-RIGHT: auto; BORDER-BOTTOM: 0px; POSITION: relative; TOP: 0px; HEIGHT: 1000px; TEXT-ALIGN: center
}
#note {
FONT-SIZE: 8pt; BACKGROUND: #646464; MARGIN-LEFT: auto; COLOR: #999999; MARGIN-RIGHT: auto; FONT-FAMILY: trebuchet ms, arial, helvetica; TEXT-ALIGN: center
}
H1 {
MARGIN: 0px
}
H2 {
MARGIN: 0px
}
H3 {
MARGIN: 0px
}
H4 {
MARGIN: 0px
}
H5 {
MARGIN: 0px
}
H4.gold {
COLOR: #c69b1d
}
HR.c {
BORDER-RIGHT: 0px; BORDER-TOP: #bbbbbb 1px dashed; MARGIN-BOTTOM: 10px; BORDER-LEFT: 0px; WIDTH: 100%; BORDER-BOTTOM: 0px; HEIGHT: 1px; TEXT-ALIGN: center
}
#tablebreak {
BACKGROUND: #646464
}
#stat1 {
FONT-WEIGHT: bold; COLOR: #ffffff; font-size:12px
}
#grey {
FONT-WEIGHT: bold; FONT-SIZE: 8pt; COLOR: #999999
}
.red {
FONT-WEIGHT: bold; COLOR: #cc0000
}
.red2 {
FONT-WEIGHT: bold; FONT-SIZE: 8pt; COLOR: #cc0000
}
#greybold {
FONT-WEIGHT: bold; COLOR: #cccccc
}
#statgreen {
FONT-WEIGHT: bold; COLOR: #33ff00; font-size:12px;
}
#pagecontent {
PADDING-RIGHT: 10px; PADDING-LEFT: 10px; BACKGROUND: #e1e1e1; PADDING-BOTTOM: 10px; VERTICAL-ALIGN: top; WIDTH: 600px; PADDING-TOP: 10px; TEXT-ALIGN: left
}
#stats {
BORDER-RIGHT: 0px; PADDING-RIGHT: 0px; BORDER-TOP: 0px; PADDING-LEFT: 0px; BACKGROUND: url(statbg.gif) #646464 no-repeat; LEFT: 880px; PADDING-BOTTOM: 0px; VERTICAL-ALIGN: middle; BORDER-LEFT: 0px; WIDTH: 116px; LINE-HEIGHT: 16px; PADDING-TOP: 2px; BORDER-BOTTOM: 0px; POSITION: absolute; TOP: 4px; HEIGHT: 37px; TEXT-ALIGN: center
}
#toplogo {
BORDER-RIGHT: 0px; BORDER-TOP: 0px; BACKGROUND: #646464; LEFT: 0px; MARGIN-LEFT: auto; BORDER-LEFT: 0px; WIDTH: 1000px; MARGIN-RIGHT: auto; BORDER-BOTTOM: 0px; POSITION: relative; TOP: 0px; HEIGHT: 45px; TEXT-ALIGN: center
}
#navbar {
BORDER-RIGHT: 2px solid; BORDER-TOP: 2px solid; BACKGROUND: url(navbg.gif) #c69b1d; LEFT: auto; MARGIN-LEFT: auto; BORDER-LEFT: 2px solid; MARGIN-RIGHT: auto; BORDER-BOTTOM: 2px solid; POSITION: absolute; TOP: 45px; HEIGHT: 20px; TEXT-ALIGN: center
}
#links {
BORDER-RIGHT: 0px; BORDER-TOP: 0px; MARGIN-LEFT: auto; BORDER-LEFT: 0px; WIDTH: 600px; MARGIN-RIGHT: auto; BORDER-BOTTOM: 0px; HEIGHT: 20px; TEXT-ALIGN: center
}
A {
BORDER-RIGHT: medium none; BORDER-TOP: medium none; BORDER-LEFT: medium none; BORDER-BOTTOM: medium none
}
IMG {
BORDER-RIGHT: medium none; BORDER-TOP: medium none; BORDER-LEFT: medium none; BORDER-BOTTOM: medium none
}
A.nav:link {
FONT-WEIGHT: bold; FONT-SIZE: 9pt; COLOR: #000000; TEXT-DECORATION: none
}
A.nav:visited {
FONT-WEIGHT: bold; COLOR: #000000; TEXT-DECORATION: none
}
A.nav:hover {
TEXT-DECORATION: underline
}
A.pix:link {
BORDER-RIGHT: medium none; BORDER-TOP: medium none; BORDER-LEFT: medium none; BORDER-BOTTOM: medium none
}
A.pix:visited {
BORDER-RIGHT: medium none; BORDER-TOP: medium none; BORDER-LEFT: medium none; BORDER-BOTTOM: medium none
}
A.pix:hover {
BORDER-RIGHT: 5px; BORDER-TOP: 5px; BORDER-LEFT: 5px; BORDER-BOTTOM: 5px
}
A:link {
FONT-WEIGHT: bold; FONT-SIZE: 9pt; COLOR: #000099; TEXT-DECORATION: none
}
A:visited {
FONT-WEIGHT: bold; COLOR: #000099; TEXT-DECORATION: none
}
A:hover {
TEXT-DECORATION: underline
}



















.black_simple
{
font-family: Verdana;
font-size: 11px;
color: #000000;
}
.small_black_simple
{
font-family: Verdana;
font-size: 9px;
color: #000000;
}
.black_heading
{
font-family: Verdana;
font-weight:bold;
font-size: 11px;
color: #000000;
}
.black_brown_heading
{
font-family: Verdana;
font-weight:bold;
font-size: 11px;
color: #333333;
}
.big_black_brown_heading
{
font-family: Verdana;
font-weight:bold;
font-size: 13px;
color: #333333;
}

.brown_simple
{
font-family: Verdana;
font-size: 11px;
color: #990000;
}
.gray_simple
{
font-family: Verdana;
font-size: 11px;
color: #999999;
}

.white_text_heading
{
font-family: Verdana;
font-size: 11px;
font-weight: bold;
color: #FFFFFF;
}

/*
A:link {
FONT-WEIGHT: bold; FONT-SIZE: 9pt; COLOR: #000000; TEXT-DECORATION: none;
}
A:visited {
FONT-WEIGHT: bold; COLOR: #000000; FONT-SIZE: 9pt; TEXT-DECORATION: none
}
A:hover {
TEXT-DECORATION: underline; COLOR: #FF0000; FONT-SIZE: 9pt;
}

*/

.button
{
BORDER: 2px #8496ce ridge;
PADDING-RIGHT: 3px;
PADDING-LEFT: 3px;
FONT-WEIGHT: bold;
FONT-SIZE: 11px;
PADDING-BOTTOM: 1px;
WIDTH: auto; COLOR: #ffffff;
PADDING-TOP: 1px;
FONT-FAMILY: Arial, Helvetica, sans-serif;
BACKGROUND-COLOR: #0B1A45;
}

.g {

position: absolute;

border: 0;

z-index: 3;

align: center;

}
.textbox_focus{color:#000000;border: 1px solid #FF8B2D;background-image: url('../../images/textarea_back_focus.gif')}

Creo que en el BODY te podria funcionar
margin: 0 auto

Hola Francisco1, le he colocado el margin: 0 auto, pero sigue igual

Prueba a crear un contenedor total que cubra todos los <div>
Ponle una anchura width el total de la web y el margin 0 auto

hola francisco.. nose como se ase,, nose de programacion... si me puedes dar una ayudita mucho mejor

Francisco este es el codigo header. php de mi web....

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE>The Million Dollar Homepage - Own a piece of internet history!</TITLE>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META
content="million dollar homepage, home, page, million, dollar, pixels, pixel, alex tew, alex, tew, student, entrepreneur, internet, millionaire, university, degree, business, marketing, ideas, advertising, banner, ad, links"
name=keywords>
<META
content="The website of Alex Tew, a 21-year-old entrepreneur, who hopes to pay his way through university by selling 1 million pixels of internet ad space for $1 each."
name=description>
<META content=ALL name=ROBOTS>
<META content="MSHTML 6.00.2600.0" name=GENERATOR></HEAD>
<body leftmargin="0" topmargin="0">
<link rel="stylesheet" href="style_lib/style.css" type="text/css">
<table width="1004" border="0" cellspacing="0" cellpadding="0" background="images/g_back_03.gif">
<tr>
<td>
<table align="center" width="1000" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="46" background="images/g_back_03.gif">
<table width="1000" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="46" width="378"> <table width="378" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="8" colspan="2">&nbsp;</td>
</tr>
<tr>
<td height="38" width="12">&nbsp;</td>
<td height="38" width="366"><a href="index.php"><img src="images/million_dollar_homepage_05.gif" border="0" width="366" height="38"></a></td>
</tr>
</table></td>
<td height="46" width="29">&nbsp;</td>
<td height="46" width="429"><table width="429" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="8">&nbsp;</td>
</tr>
<tr>
<td height="38"><img src="images/text_img_13.gif" width="429" height="38" border="0" usemap="#Map"></td>
</tr>
</table></td>
<td height="46" width="43">&nbsp;</td>

<td height="46" width="121" ><img src="images/right_oval1_09.gif" width="121" height="53"></td>
</tr>
</table>

</td>
</tr>
<tr>
<td height="21" background="images/y_back_03.gif"><TABLE style="left:0; top:100;" height=20 cellSpacing=0 cellPadding=0 width=1000 border=0>
<TBODY>
<TR>
<TD> <FORM style="MARGIN: 0px" action="newsletter.php" method=post>
<FONT
style="FONT-WEIGHT: bold; COLOR: #ffffff">Get my newsletter: </FONT>
<INPUT style="FONT-SIZE: 8pt; HEIGHT: 18px"
value=[correo eliminado] name=email>
<INPUT style="FONT-SIZE: 8pt; HEIGHT: 18px" type=submit value=Go! name=submit >
</FORM></TD>

<TD><A class=nav
href="index.php">Home</A> &nbsp;|&nbsp; <A class=nav
href="buypixel.php">Buy Pixels</A> &nbsp;|&nbsp; <a class="nav" href="faq.php">FAQ</a>
&nbsp;|&nbsp; <A class=nav
href="blog.php">Blog</A> &nbsp;|&nbsp; <A class=nav
href="pixellist.php">Pixel List</A> &nbsp;|&nbsp; <A class=nav
href="press.php">Press</A>
<!--<img src="./img-site/new.gif" width=28 height=11>-->
&nbsp;|&nbsp; <a class="nav" href="casestudy.php">Case Study
</a>&nbsp;|&nbsp; <a class="nav" href="tellafriend.php">Tell
a friend</a> &nbsp;|&nbsp; <a class="nav" href="contactus.php">Contact
me</a> </TD>
</TR>
</TBODY>
</TABLE></td>
</tr>
</table>
<?php

require("includes/configure.php");
require("includes/database_tables.php");

$sql = "select x1,y1,x2,y2 from " . TABLE_ORDER . " ";

$link = mysql_query($sql);

$sum=0;

while($data=mysql_fetch_row($link)){
$sum=$sum+( ( ($data[2]-$data[0])*($data[3]-$data[1])) *100);
}

function num_form($take){
$n=strlen($take);
if ($n>6) $take=substr($take, -$n, $n-6).",".substr($take, -6, 3).",".substr($take, -3, 3);
elseif($n>3) $take=substr($take, -$n, $n-3).",".substr($take, -3, 3);
return $take;
}

?>
<DIV style="position:absolute; left:887; top: 11 ; z-index:0">
<FONT id=stat1>Sold:</FONT><FONT id=statgreen><? echo num_form($sum); ?></FONT><BR>
<FONT id=stat1>Available:</FONT><FONT id=statgreen><?php echo num_form(1000000-$sum); ?></FONT>
</DIV>


</td>
</tr>
<tr>
<td height="1000" align="center">
<map name="Map">
<area shape="rect" coords="42,17,386,36" href="casestudy.php">
</map>

Deverias aprender un poquito el header es solo un archivo
Deverias crear un contenedor si no lo puedes centrar en el body en todas las paginas de tu web index.php etc.php en <div="contenedor">
Y despues todos los demas </div>
Y en los css creas el
#contenedor {
width total
margin 0 auto
}

gracias... lo boy a probar