intuit partner platform - QBD Query Documentation -

I have read the documentation to build QBD questions here:

and full SDK documentation here:

I am trying to create a query in C # and Net SDK 2.0 which takes a customer number from the text field and gives all invoices by that customer. Here's what I've done so far:

  var qbdInvoiceQuery = New Intuit.ipp.Data.Qbd.InvoiceQuery (); QbdInvoiceQuery.Item = "1"; QbdInvoiceQuery.ChunkSize = "10"; Var qbd Invoices = qbdInvoiceQuery.ExecuteQuery & lt; Intuit.ipp.Data.Qbd.Invoice & gt; (Context) .toList (); GrdQuickBooksInvoices.DataSource = qbdInvoices;   
 It works well, but I get all the invoices. I have a good example of the query example above, but I can not find the documentation for filter outside the CDCoffoff.   
 
 
 You need to create a filter on the invoice query to receive invoices related to a specific customer. You can do something like that.  
  & lt ;? XML version = "1.0"? & Gt; & Lt; InvoiceQuery xmlns = "http://www.intuit.com/sb/cdm/v2" & gt; Add more tags & gt; Invoice / header / customer name & lt; / Includegate & gt; & Lt; / InvoiceQuery & gt;   
 Thanks, 
 Watery