asp下比较全面的获取IP地址的代码

<%Private Function getIP()  
Dim strIPAddr  
If Request.ServerVariables("HTTP_X_FORWARDED_FOR") = "" OR InStr(Request.ServerVariables("HTTP_X_FORWARDED_FOR"), "unknown") > 0 Then  
strIPAddr = Request.ServerVariables("REMOTE_ADDR")  
ElseIf InStr(Request.ServerVariables("HTTP_X_FORWARDED_FOR"), ",") > 0 Then  
strIPAddr = Mid(Request.ServerVariables("HTTP_X_FORWARDED_FOR"), 1, InStr(Request.ServerVariables("HTTP_X_FORWARDED_FOR"), ",")-1)  
ElseIf InStr(Request.ServerVariables("HTTP_X_FORWARDED_FOR"), ";") > 0 Then  
strIPAddr = Mid(Request.ServerVariables("HTTP_X_FORWARDED_FOR"), 1, InStr(Request.ServerVariables("HTTP_X_FORWARDED_FOR"), ";")-1)  
Else  
strIPAddr = Request.ServerVariables("HTTP_X_FORWARDED_FOR")  
End If  
getIP = Trim(Mid(strIPAddr, 1, 30))  
End Function 
ip=getIP() 
response.write(ip) 
%>