function hr(div,url){ 
	var req=false;
	if(window.XMLHttpRequest){
		req=new XMLHttpRequest();
	}else if(window.ActiveXObject){
		req=new ActiveXObject("Microsoft.XMLHTTP");
	}
	req.open("GET",url,true);
	req.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
	req.onreadystatechange=function(){
		if(req.readyState==4){
			dd(div,req.responseText);
		}
	}
	req.send(null);
} 

function dd(div,res){ 
	if(document.layers){
		var lay=document.layers[div].document;
		lay.open();
		lay.write(res);
		lay.close();
	}else if(parseInt(navigator.appVersion)>=5&&navigator.
appName=="Netscape"){
		document.getElementById(div).innerHTML=res; 
	}else if(document.all){ 
		document.all[div].innerHTML=res; 
	}
	return true; 	
} 

hr('filelist','http://www.nhacd.org/envirothon/2009/webFiles/webFiles.php?u=ajax');