Using ruby soap client with nusoap server?

i try ruby soap client with nusoap server,but server can’t get argument
please help me thanks

ruby client:
factory =
SOAP::WSDLDriverFactory.new(“http://www.winson.idv.tw/mytest/nusoap/demo.php?wsdl”)
soap = factory.create_rpc_driver
soap.wiredump_file_base = “log_file”
begin
soapResponse =
soap.getBook(“winson”,“winson”,“winson”,“winson”,“winson”,“winson”)
rescue ::XSD::ValueSpaceError => e
puts e.to_s
end

ruby soap log : argument is all nil?? why?

<?xml version="1.0" encoding="utf-8" ?>

maybe

soap.getBook(:Method => “winson”,:LoginID => “winson”, …)