[englndpatriots]

For those that want one W3C Validated I tried but no luck. I managed to kill 2 errors though.

<style type="text/css">
<!--
#sponsorAdDiv {position:absolute; height:1; width:1px; top:0; left:0;}
-->
</style>
<script type="text/javascript">


/******************************************
* DHTML Ad Box (By Matt Gabbert at http://www.nolag.com)
* Visit http://www.dynamicdrive.com/ for full script
* This notice must stay intact for use
******************************************/

adTime=20;  // seconds ad reminder is shown
chanceAd=1; 
var ns=(document.layers);
var ie=(document.all);
var w3=(document.getElementById && !ie);
var calunit=ns? "" : "px"
adCount=0;
function initAd(){
    if(!ns && !ie && !w3) return;
    if(ie)        adDiv=eval('document.all.sponsorAdDiv.style');
    else if(ns)    adDiv=eval('document.layers["sponsorAdDiv"]');
    else if(w3)    adDiv=eval('document.getElementById("sponsorAdDiv").style');
    randAd=Math.ceil(Math.random()*chanceAd);
        if (ie||w3)
        adDiv.visibility="visible";
        else
        adDiv.visibility ="show";
    if(randAd==1) showAd();
}
function showAd(){
if(adCount<adTime*10){adCount+=1;
    if (ie){documentWidth  =truebody().offsetWidth/2+truebody().scrollLeft-20;
    documentHeight =truebody().offsetHeight/2+truebody().scrollTop-20;}    
    else if (ns){documentWidth=window.innerWidth/2+window.pageXOffset-20;
    documentHeight=window.innerHeight/2+window.pageYOffset-20;} 
    else if (w3){documentWidth=self.innerWidth/2+window.pageXOffset-20;
    documentHeight=self.innerHeight/2+window.pageYOffset-20;} 
    adDiv.left=documentWidth-200+calunit;adDiv.top =documentHeight-200+calunit;
    setTimeout("showAd()",100);}else closeAd();
}
function closeAd(){
if (ie||w3)
adDiv.display="none";
else
adDiv.visibility ="hide";
}

function truebody(){
return (document.compatMode && document.compatMode!="BackCompat")? document.documentElement : document.body
}

onload=initAd;
//End-->
</script>
<!-- Inizio script -->
<if condition="$show['guest']">
<if condition="THIS_SCRIPT == 'index'">
<div id="sponsorAdDiv" style="visibility:hidden">
<table width="450px" height="350px" bgcolor="#008000"><tr><td>
<table width="445px" height="345px" bgcolor="#F0FFF0"><tr><td align="center" valign="middle">

<!-- here your message -->
<a href="$vboptions[forumhome].php$session[sessionurl_q]"><img src="$stylevar[titleimage]" border="0" alt="$vboptions[bbtitle]" /></a>
<p><b>Wellcome to $vboptions[bbtitle]<br />
To be able to use our forum you only need to <a href="$vboptions[bburl]/register.php" title="Register to $vboptions[bbtitle]">register</a>.</b>
</p>

<br />

<!-- /here your message -->
</td></tr></table></td></tr></table>
</div>
</if>
</if>
<!-- fine script -->