Wrap a request in a Soap Envelope?

I have a request without the SOAP information, but I need to wrap it in a SOAP envelope. In the past I have manually built the envelope using StringBuilder and put the request in the body, but is there a better, more generic way? An example would be helpful.

Example:

I will have something like the following:

<UpdateQuantity>
开发者_开发技巧   <Product id="1234"></Product>
   <Qty>10</Qty>
</UpdateQuantity>

So as I said above, I have just built the SOAP envelope using a StringBuilder and put the above xml in the body portion. Is it best to just stick with that approach or is there a more generic way? Should I write a method that takes all the SOAP parameters that can change with a request and still using a StringBuilder?

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If you want to execute a service you need access to the service WSDL..isn't it? If it is a single service, How come requests differs client to client? The best way to me get your service wsdl and use axiom library to create standard soap messages..