var xmlHttp
function showHint(str)
{ 
	if (str.length > 0)
	{ 
		document.getElementById("d_uname").innerHTML="验证帐号....";
		var url="checkuser.asp?sid=" + Math.random() + "&uID=" + str
		xmlHttp=GetXmlHttpObject(stateChanged)
		xmlHttp.open("GET", url , true)
		xmlHttp.send(null)
	} 
	else
	{ 
		return false;
	} 
} 

function stateChanged() 
{ 
	if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
	{ 
		if (xmlHttp.responseText =="true")
		{
			document.getElementById("d_uname").innerHTML= "  " +"恭喜你，此帐号未被使用，您可以注册！";
			document.getElementById("d_uname").className= "d_ok";
			document.getElementById("d_uname_img").src=li_ok;
			document.getElementById("uname2").value= "YES";
			return true;
		}
		else if(xmlHttp.responseText =="false")
		{
			document.getElementById("d_uname").innerHTML= "  " +"对不起,此帐号已经存在,请更换一个其他帐号！";
			document.getElementById("d_uname").className= "d_err";
			document.getElementById("d_uname_img").src=li_err;
			document.getElementById("uname2").value= "NO";
			return true;
		}
		else
		{
			return false;
		}
	} 
	else

	return false;
} 

function GetXmlHttpObject(handler)
{ 
	var objXmlHttp=null

	if (navigator.userAgent.indexOf("Opera")>=0)
	{
		alert("This example doesn't work in Opera") 
		return; 
	}
	if (navigator.userAgent.indexOf("MSIE")>=0)
	{ 
		var strName="Msxml2.XMLHTTP"
		if (navigator.appVersion.indexOf("MSIE 5.5")>=0)
		{
			strName="Microsoft.XMLHTTP"
		} 

		try
		{ 
			objXmlHttp=new ActiveXObject(strName)
			objXmlHttp.onreadystatechange=handler 
			return objXmlHttp
		} 
		catch(e)
		{ 
			alert("Error. Scripting for ActiveX might be disabled") 
			return 
		} 
	} 
	if (navigator.userAgent.indexOf("Mozilla")>=0)
	{
		objXmlHttp=new XMLHttpRequest()
		objXmlHttp.onload=handler
		objXmlHttp.onerror=handler 
		return objXmlHttp
	}
}