Run Time error, plz help

[Discusman]

I get this error after I run the program:

ADODB.Fields error '800a0bb9'

Arguments are of the wrong type, are out of acceptable range, or are in conflict with one another.

/test2.asp, line 7

Line 7:
objConfig.Fields(cdoSendUsingMethod)=cdoSendUsingPort

The complete program as follow:
====================================
Dim objMail
Set objMail = Server.CreateObject("CDO.Message")
Set objConfig = Server.CreateObject("CDO.Configuration")

'Configuration:
objConfig.Fields(cdoSendUsingMethod)=cdoSendUsingPort
objConfig.Fields(cdoSMTPServer)="localhost"
objConfig.Fields(cdoSMTPServerPort)=25
objConfig.Fields(cdoSMTPAuthenticate)=cdoBasic

'Update configuration
objConfig.Fields.Update
Set objMail.Configuration = objConfig

objMail.From ="admin@hotmail.com"
objMail.To = "user@hotmail.com"
objMail.Subject ="Contact from your site"
objMail.TextBody="This is a test for CDO.message"
objMail.Send

Set objMail=Nothing
Set objConfig=Nothing

Response.Redirect "RegistrationInProcess2.asp"