... XMLAddChild(doc,"soap:Header","",True) XMLAddAttribute(doc,"xmlns:wsa","http://www.w3.org/2005/08/addressing") XMLAddChild(doc,"wsa:Action","http://tempuri.org/IWcfCP/Autenticar") XMLAddChild(doc,"wsa:To","https://zofri.mekanosige.cl:2414/WcfCP.svc") ...