var http_request=false;
function send_request(url){
http_request=false; 

if(window.XMLHttpRequest){
	http_request=new XMLHttpRequest();
	if(http_request.overrideMimeType){
		http_request.overrideMimeType("text/xml"); 
	}
}

else if(window.ActiveXObject){
	try{ http_request=new ActiveXObject("Msxml2.XMLHttp"); 
	}
	catch(e){
		try{ http_request=new ActiveXobject("Microsoft.XMLHttp");
		}
	catch(e){}
	} 
}

if(!http_request){
	window.alert("创建XMLHttp对象失败！"); 
	return false;
}

http_request.onreadystatechange=processrequest;  
http_request.open("GET",url,true);
http_request.send(null);
}


function processrequest(){ 
if(http_request.readyState==4){
	if(http_request.status==200){
	document.getElementById(reobj).innerHTML=http_request.responseText; 
	} else{
	alert("您所请求的页面不正常！"); 
	}
} 
}


function usercheck(obj){ 
//var f=document.reg; 
send_request('check.php?id='+obj); 
reobj=obj; 
//document.getElementById(reobj)=obj;
}