How to place JavaScript ad using ad_html?

Hi.

Can you tell me, how to place ad using JavaScript code?

I have code like this:

<!-- StartCode: ..... --> 
<script language='JavaScript' type='text/javascript'> 
/* <![CDATA[ */ 
var bbs=screen,bbn=navigator,bbh;bbh='&ubl='+bbn.browserLanguage+'&ucc='+bbn.cpuClass+'&ucd='+bbs.colorDepth+'&uce='+bbn.cookieEnabled+'&udx='+bbs.deviceXDPI+'&udy='+bbs.deviceYDPI+'&usl='+bbn.systemLanguage+'&uje='+bbn.javaEnabled()+'&uah='+bbs.availHeight+'&uaw='+bbs.availWidth+'&ubd='+bbs.bufferDepth+'&uhe='+bbs.height+'&ulx='+bbs.logicalXDPI+'&uly='+bbs.logicalYDPI+'&use='+bbs.fontSmoothingEnabled+'&uto='+(new Date()).getTimezoneOffset()+'&uti='+(new Date()).getTime()+'&uui='+bbs.updateInterval+'&uul='+bbn.userLanguage+'&uwi='+bbs.width; 
document.write("<scr"+"ipt  language='JavaScript' type='text/javascript' src='http://......."+bbh+"&alttext=0&border=0&bust="+Math.random()+"&target=_blank'><"+"\/scr"+"ipt>");
/* ]]> */ 
</script> 
<noscript> 
<a href="http://...." target="_blank"><img src="http://...." border='0' alt='' /></a> 
</noscript> 
<!-- EndCode: ...... --> 

After pasting this code into html_ad it appears on the site instead of being replaced by image banner.