Lo script lo metti nei tag <head>...</head>
codice:
<script language="javascript">
<!--
onload=function(){
var lar;
var alt;
var sW=screen.width;
var sH=screen.height;
if(sW==800 && sH==600){
lar = 800;
alt = 600;
}else{
lar = 960;
alt = 720;
}
document.getElementById('swf').innerHTML='<object classid="clsid27CDB6E-AE6D-11cf-96B8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=7,0,19,0" width="' + lar + '" height="' + alt + '" ID="sf" VIEWASTEXT><param name="movie" value="quiz.swf" /><param name="quality" value="high" /><param name="wmode" value="window" /><param name="allowScriptAccess" value="always" /><param name="allowFullScreen" value="true" /><embed src="quiz.swf" quality="high" name="sf" allowScriptAccess="always" allowFullScreen="true" pluginspage="http://www.macromedia.com/go/getflashplayer" type="application/x-shockwave-flash" width="' + lar + '" height="' + alt + '" /></object>';
}
</script>
il div nel body dove vuoi
<div id="swf"align="center"></div>