AIF: Sales invoice service

salesinvoicenew.SalesInvoiceServiceClient client = new salesinvoicenew.SalesInvoiceServiceClient();
salesinvoicenew.CallContext callcontext = new salesinvoicenew.CallContext();
salesinvoicenew.AxdSalesInvoice invoice = new salesinvoicenew.AxdSalesInvoice();

callcontext.Company = "ceu";
callcontext.Language = "en-us";

QueryCriteria qc = new QueryCriteria();
qc.CriteriaElement = new CriteriaElement[1];
qc.CriteriaElement[0] = new CriteriaElement();
qc.CriteriaElement[0].DataSourceName = "CustInvoiceJour";
qc.CriteriaElement[0].FieldName = "SalesId";
qc.CriteriaElement[0].Operator = Operator.Equal;
qc.CriteriaElement[0].Value1 = "SO-101281";

try
{
    invoice = client.find(callcontext, qc);
    Console.Write("success");
    Console.ReadLine();
}
catch(Exception ex)
{
    Console.Write(ex);
}