<%
Response.Write "document.write('<center>如何获取用户真实的IP地址</center><P>');"
Dim UserIP
UserIP = Request.ServerVariables("HTTP_X_FORWARDED_FOR")
If UserIP = "" Then
    UserIP = Request.ServerVariables("REMOTE_ADDR")
End If
Response.Write "document.write('用户真实的IP是"&UserIP&"');"
%>
<SCRIPT language=javascript src="readip.asp"></SCRIPT>
或者用xmlhttp也行..