How to find the real IP address with ASP

As we all know, the way to get an IP address is

The following are the referenced contents: <%=request.servervariables ("REMOTE_ADDR")%>

But if the client uses the proxy server, then uses this method to obtain is the proxy server's IP, below is penetrates the server to obtain the real IP the code:

The following are the referenced contents: function GetIP () Dim realip,proxy Realip = Request.ServerVariables ("Http_x_forwarded_for") Proxy = Request.ServerVariables ("REMOTE_ADDR") If Realip = "" Then GetIP = Proxy Else GetIP = Realip End If End Function