wow新手月卡:如何让浮标广告在其他广告位的上面移动？

<DIV id=img style="HEIGHT: 90px; LEFT: 12px; POSITION: absolute; TOP: 3px; WIDTH: 90px">
<embed src='piao/jnht.swf' quality='high' width='200' height='200' type='application/x-shockwave-flash' wmode='transparent' ></embed>
<SCRIPT language=JavaScript><!-- Begin
var xPos=500;var yPos=document.body.clientHeight;var step=4;var delay=80;var height=0;var Hoffset=0;var Woffset=0;var yon=0;var xon=0;var pause=true;var interval;img.style.top=yPos;function changePos(){width=document.body.clientWidth;height=document.body.clientHeight;Hoffset=img.offsetHeight;Woffset=img.offsetWidth;img.style.left=xPos+document.body.scrollLeft;img.style.top=yPos+document.body.scrollTop;if(yon){yPos=yPos+step;}else{yPos=yPos-step;}if(yPos<0){yon=1;yPos=0;}if(yPos>=(height-Hoffset)){yon=0;yPos=(height-Hoffset);}if(xon){xPos=xPos+step;}else{xPos=xPos-step;}if(xPos<0){xon=1;xPos=0;}if(xPos>=(width-Woffset)){xon=0;xPos=(width-Woffset);}}function start(){img.visibility='visible';interval=setInterval('changePos()',delay);}start();
//--></SCRIPT>
</div>

www.0533fc.com
现在它每次都出现在其他广告位的下面

能不能让它在上面显示？而且只在网页的中间位置移动呢？
谢谢