désolé votre code xhtml n'est pas valide, voici votre code :
<?phpswitch($KND['document']) {case "presentation": $page = "documents/presentation.php"; break;case "devis": $page = "documents/devis.php"; break;case "partenaires": $page = "documents/partenaires.php"; break;case "legales": $page = "documents/legales.php"; break;case "mra": $page = "modules/mra-admin/mra.tpl"; break;}if(empty($page)) $page = "documents/presentation.php";?><div><table class="head"><colgroup><col style="width:500px;"/><col style="width:200px;"/></colgroup><tbody><tr><td class="content"><table width="700" height="110" border="0" cellpadding="0" cellspacing="0"><tbody><tr><td class="tr00td00" colspan="3"><img src="images/eco_01.jpg" width="700" height="38" alt=""/></td></tr><tr><td class="tr01td00" rowspan="2"><img src="images/eco_02.jpg" width="22" height="104" alt=""/></td><td class="tr01td01"><object type="application/x-shockwave-flash" data="images/eco.swf" width="227" height="99"><param name="movie" value="images/eco.swf"/><param name="quality" value="high"/></object></td><td class="tr01td02" rowspan="2"><img src="images/eco_04.jpg" width="451" height="104" alt=""/></td></tr><tr><td class="tr02td00"><img src="images/eco_05.jpg" width="227" height="5" alt=""/></td></tr></tbody></table></td><!--<td class="l">LOGO ENSEIGNE A FAIRE</td><td class="r"><div class="l"><img src="images/ecologie.png" alt="100% écologique"/></div><div class="r"><img src="images/ISO14001.gif" alt="ISO 14001"/></div></td>--></tr></tbody></table><table class="menu"><tbody><tr><td class="l"></td><td class="c"><ul><li><a href="?document=presentation">Présentation</a></li><li><a href="?document=devis">Demande de devis</a></li><li><a href="?document=legales">Mentions Légales</a></li><li><a href="?document=partenaires">Partenaires</a></li></ul></td><td class="r"></td></tr></tbody></table><table class="info"><tbody><tr><td class="l"></td><td class="c"><div class="street"><p>34 rue Borville Dupuis</p><p>27000 Evreux</p></div><div class="phone">02.32.33.01.40</div><div class="fax">02.32.35.40.69</div><div class="mail"><a href="mailto:contact@jeveuxdecapermesmeubles.com">contact</a></div></td><td class="r"></td></tr></tbody></table><table class="body"><thead><tr><td class="l"></td><td class="c"></td><td class="r"></td></tr></thead><tfoot><tr><td class="l"></td><td class="c"></td><td class="r"></td></tr></tfoot><tbody><tr><td class="l"></td><td class="c" id="test"><?php require_once($page); ?></td><td class="r"></td></tr></tbody></table><div class="copyright"><div class="kenada"><div><a href="http://jeveuxdecapermesmeubles.com/" class="com">jeveuxdecapermesmeubles.com</a><span> © <?php echo date('Y'); ?> </span></div><div><span>powered by</span><a href="http://kenada.fr/" class="kenada">kenada</a></div></div><a href="http://jigsaw.w3.org/css-validator/check/referer" class="w3c"><img src="images/logo-css.png" alt="CSS level 2.1" title="CSS level 2.1"/></a><a href="http://validator.w3.org/check/referer" class="w3c"><img src="images/logo-xhtml.png" alt="XHTML 1.0 Strict" title="XHTML 1.0 Strict"/></a><div class="browsers safari" title="Compatible Safari 3"></div><div class="browsers opera" title="Compatible Opera 9"></div><div class="browsers ie" title="Compatible Internet Explorer 6"></div><div class="browsers firefox" title="Compatible Firefox 2"></div></div><?phpif(!empty($_SESSION['admin'])) {switch($page) {case "documents/presentation.php": $js = "documents/presentation.html"; break;case "documents/devis.php": $js = "documents/devis.html"; break;case "documents/partenaires.php": $js = "documents/partenaires.html"; break;}if(!empty($js)) {?><style type="text/css">@import url('modules/cms/cms.css');</style><script type="text/javascript" src="kenada/kenada.js"></script><script type="text/javascript">var iframePath = "<?=$js;?>";</script><script type="text/javascript" src="modules/cms/cms.js"></script><?php}}?></div>