How to pass input for a function in webservice as XML?

Hi All,
      Suppose i have one function which is defined in web service that
is save_request(int,string,int).So i wanna pass the inputs in this
function like XML format.
web service also in ROR and i am creating one application in ROR where i
have to integrate with web service now i wanna pass input as XML in
webservices functions.

Please help me out.

Looking for your suggestions.

Thanks & Regards,
Varun Goel

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