How to control the SOAP message in the C# server code ?

I have a question regarding Soap Response.

My C# Web Services Server code looks like this

[WebMethod]
public XmlDocument NodePing(string strXml)
{
code parses the string and responds to Client.
}

In the SOAP Response, I am seeing the following SOAP message.

<?xml version="1.0" encoding="utf-8"?><soap:Envelope
xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"><soap:Body><NodePingResponse
xmlns="http://localhost/NetworkNode"><NodePingResult><tns:PingResponse
xmlns:tns="http://www.neien.rg/schema/v1.0/cdx.xsd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
soapenv:encodingStyle="http://schema.xmlsoap.org/soap/encoding/"
xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<return type="xsd:string" xmlns="">Ready</return>
</tns:PingResponse></NodePingResult>
</NodePingResponse></soap:Body></soap:Envelope>

My requirement is, I should somehow not to send <NodePingResponse> and <NodePingResult>
tags in the SOAP Body. I should control this on
the Server code itself.

Can anyone answer this please ?

Thanks,
Mahesh