ThaiSEOBoard.com

.idivcenter {
margin: 0 auto;
}
#pagewrapper {
	height:auto;
}
#header-wrap {
float:none;
margin: 0 auto;
width: 960px;
}
#left-header {
	float: left;
	border: 0px;
	width: 89px;
	height: 168px;
	background-image:url("images/idx-xheader_l.png");
}

#right-header {
	float: right;
	border: 0px;
	width: 86px;
	height: 168px;
	background-image:url("images/idx-xheader_r.png");
	
}

#center-header {
	float: left;
	border: 0px;
	width: 785px;
	height: 168px;
	background-image:url("images/idx-xheader.png");
}

#zfooter {
	clear: both;
	background: #A2A2A2;
}
#bodywrap {
	clear:both;
	min-height :300px;
	width: 960px;
	margin: 0 auto;
	height:auto;
	height: 100%;
}
#zleftbg {
	min-height :300px;
	width: 89px;
	height: 100%;
	float:left;
	background-repeat:repeat;
	background-image: url("images/idx-bgl.png");
}
#zrightbg {
	min-height :300px;
	width: 86px;
	height: 100%;
	float:right;
	background-repeat:repeat;
	background-image: url("images/idx_bgr.png");
}
#zcontentwrap {
	width: 785px;
	min-height :300px;
	float:left;
	line-height: 13px;
}
body,td,th {
	font-family: Tahoma;
	font-size: 12px;
}

#adsense-bottomwrap {
	margin: 0 auto;
	width: 960px;
	clear: both;
}

#footer-wrap {
	margin: 0 auto;
	width: 960px;
	margin-top: 0px;
}
#footer-l {
	float: left;
	width: 89px;
	height: 258px;
	background-image:url("images/idx-xfooter_l.png");
}
#footer-r {
	float: right;
	width: 86px;
	height: 258px;
	background-image:url("images/idx-xfooter_r.png");
}
#footer-center {
	float: left;
	width: 785px;
	height: 211px;
	background-image:url("images/idx-xfooter.png");
}
#footer-cpr_l {
	float: left;
	width: 175px;
	height: 47px;
	background-image:url("images/idx-xfooter_cpr-l.png");
}
#footer-cpr_r {
	float: right;
	width: 128px;
	height: 47px;
	background-image:url("images/idx-xfooter_cpr-r.png");
}
#footer-cpr_center {
	float: right;
	width: 482px;
	height: 47px;
	background-image:url("images/idx-xfooter_copyright.png");
}
#adswrap-l {
	float: left;
	min-height :100px;
	width: 89px;
	height: 100%;
	background-repeat:repeat;
	background-image: url("images/idx-bgl.png");
	border: 0px;
}
#adswrap-r {
	float: right;
	min-height :100px;
	width: 86px;
	height: 100%;
	background-repeat:repeat;
	background-image: url("images/idx_bgr.png");
	border: 0px;
}
#zadszone {
	float: left;
	min-height :100px;
	width: 785px;
}
.clear-all{clear:both; line-height:0; height:0;}
#znavileft {
	float: left;
	width: 200px;
}
#zcontent {
	float: right;
	width: 585px;
}
#etcfooter {
	margin: 0 auto;
}

<div id="pagewrapper" class="idivcenter">
  <div id="header-wrap">
    <div id="left-header"></div>
    <div id="right-header"></div>
    <div id="center-header"></div>    
  </div>
  <div id="bodywrap">
      <div id="zleftbg"></div>
      <div id="zcontentwrap" class="idivcenter">
        <div id="znavileft">
          <p>navigation</p>
        </div>
        <div id="zcontent">
          <p>content</p>
      </div>
        </div>
        <div id="zrightbg"></div>
  </div>
  <div id="adsense-bottomwrap">
  	<div id="adswrap-l"></div>
    <div id="adswrap-r"></div>
    <div id="zadszone"></div>
  </div>
  <div id="footerglobalwrap">
  <div id="footer-wrap" class="clear-all">
  	<div id="footer-l"></div>
        <div id="footer-r"></div>
        <div id="footer-center"></div>
        <div id="footer-cpr_l"></div>
        <div id="footer-cpr_r"></div>
    	<div id="footer-cpr_center">
   </div>
  </div>
   <div id="etcfooter">...</div>
  </div>
 </div>

http://www.barelyfitz.com/screencast/html-training/css/positioning/

body {
	background: #D2D6D9 url(../image/default-bg.png) center repeat-y;
	font-family: Arial, Helvetica, sans-serif;
}