I am trying to start workflow using TaskmanagmentService

Here is the code:
TaskManagementServices services = new TaskManagementServices();

initRequest initReq = new initRequest();
initReq.participantToken = (string)Session["token"];
initReq.taskId = txtInit.Text;

initRequestInput input = new initRequestInput();
input.Any = new XmlElement[1];
XmlDocument doc = new XmlDocument();
string xml = "<output xmlns:xxforms='http://orbeon.org/oxf/xml/xforms' xmlns:xs='http://www.w3.org/2001/XMLSchema' xmlns:f='http://orbeon.org/oxf/xml/formatting' xmlns:fe='http://example.com/Forms/AddCreditApplication/xform' user='demo/employee'>";
xml += "<Name_and_Surname_pasted72 />";
xml += "<Amount_pasted70 />";
xml += "<Duration_pasted68 />";
xml += "<txtName>Oleg1</txtName>";
xml += "<txtAmount>3123</txtAmount>";
xml += "<txtDuration>123</txtDuration>";
xml += "<Upload filename='' mediatype='' upload-id='Upload' /><Application_pasted58 /></output>";
doc.LoadXml(xml);
input.Any[0] = doc.DocumentElement;
initReq.input = input;

okResponse ok = new okResponse();
ok = services.initProcess(initReq);

My InitRequest is equal to Xforms request, that successed. What I am doing wrong ?