Wcf - Soap Request Client To Webservice Using .net?

How do I send/Receive SOAP messages usiung .NET I wanted to invoke a webservice, however not like the way shown in the link above.What I did was, created a service reference with the wsdl url(in a windows application with a button click event)

[URL]

have created a client object

Dim objProxy As MyClient = New MyClient()

I have populated the objrequest and objreqheader using the below methods, (assigning string values and not xml)

objreqheader.id = "abcd"

Finally the below line invokes the service

objresponsehead = objProxy.myoperation(objreqheader, objrequest, objresp)

From reference vb, this is the myoperation public function

Public Function myoperation(ByVal RequestHeader As AFA.RequestHeaderType, ByVal GetTransactionDetailsReq As AFA.GetTransactionDetailsReqType, <System.Runtime.InteropServices.OutAttribute()> ByRef GetTransactionDetailsResp As AFA.GetTransactionDetailsRespType) As AFA.ResponseHeaderType

[code]....

I checked the property of objProxy, it is having basic http binding as the property. Anyone invoked the service like this? From soapui, the response is fine, after i populate the request fields.How can i enable the trace to see what is the request going and where is the problem.