解决XML HTTP提交过时返回是乱码的问题

<script>

var xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");

xmlhttp.open("GET","http://mengxianhui/asp/xmlencode.asp",false)

xmlhttp.setRequestHeader("Content-Type","text/xml")

xmlhttp.send()

alert(xmlhttp.responseXML.xml);

var s = '<?xml version="1.0"?>

<a> 如何解决XMLHTTP提交过时返回的是乱码，这是先提交上去，再返回的文字。 </a>'

xmlhttp.open("POST","http://mengxianhui/asp/xmlencode.asp",false)

xmlhttp.setRequestHeader("Content-Type","text/xml")

xmlhttp.send(s)

alert(xmlhttp.responseXML.xml);

</script>

<%@ Language=VBScript %>

<%

Response.ContentType = "text/xml"

Response.CharSet = "GB2312"
Dim varCount,varReq,xmldom

varCount = Request.TotalBytes

varReq = Request.BinaryRead(varCount)
If Request.ServerVariables("REQUEST_METHOD") = "POST" Then

Set xmldom = Server.CreateObject("MSXML2.DOMDocument")

xmldom.load varReq

Response.Write "<?xml version=""1.0"" encoding=""GB2312""?>" & xmldom.documentElement.xml

Else

Response.Write "<?xml version=""1.0"" encoding=""GB2312""?>
<a>如何解决XMLHTTP提交过时返回的是乱码，这是从服务器直接返回的文字。</a>"

End If

%>