Update AxdSalesorder using srv SalesorderServiceClient()

Hello,

I have a salesorder on my AX 2012, i am using the SalesSalesorderService. I am unable to update the AxdSalesorder. below is my code (if there is anything wrong can you please provide me with the correct code):

public Boolean UpdateAxSalesOrder(string SalesId)

        {

            SalesOrderServiceClient proxy = new SalesOrderServiceClient();

            CallContext context = new CallContext();

            context.Company = ConfigurationManager.AppSettings["AxOrganization"].ToString();

            //Create KeyList

            CustomerService.EntityKey[] readRespKeys = new CustomerService.EntityKey[1];

            readRespKeys[0] = new CustomerService.EntityKey();

            readRespKeys[0].KeyData = new CustomerService.KeyField[1];

            readRespKeys[0].KeyData[0] = new CustomerService.KeyField();

            readRespKeys[0].KeyData[0].Field = "SalesId";

            readRespKeys[0].KeyData[0].Value = SalesId;

            //Fetch SalesOrder

            AxdSalesOrder salesOrder = null;

            salesOrder = proxy.find(context, createQueryCriteria(SalesId));

            try

            {

                if (salesOrder.SalesTable.Length > 0)

                {

                    foreach (AxdEntity_SalesTable salesTable in salesOrder.SalesTable)

                    {

                        foreach (AxdEntity_SalesLine salesLine in salesTable.SalesLine)

                        {

                            salesLine.SalesQty = 10;

                        }

                    }

                }

                proxy.update(context, readRespKeys, salesOrder);

                return true;

            }

            catch (System.ServiceModel.FaultException ex)

            {

                throw ex.Message;

            }

        }