Issue in INSERT Function - WEB Services (Sales Line)

Hello All Experts,

Currently I am working with the Sales Order Sub Form Page Web-Service in Visual Studio .NET (C#).
I am trying to insert a Sales Line in Perticular Sales Order by using the Insert Function of the Same Web Service.
I wrote as follows,

SalesOrderSubForm_Service Ss2 = new SalesOrderSubForm_Service();
            SalesOrderSubForm S2 = new SalesOrderSubForm();
            Ss2.Url = "http://spvm:7047/DynamicsNAV/WS/CRONUS_International_Ltd/Page/SalesOrderSubForm";
            Ss2.UseDefaultCredentials = true;
            S2.Document_No = "1020";
            S2.Line_No = 10000;
            Ss2.Create(ref S2);

But, through NAV code execution, I found that, it is assigning the Last record of SalesHeader table to SalesHeader record variable and since it is Released Status order, it is showing me the error "Status must be Open in Sales Header".

That means, I am unable to locate the Selected Order using this Web-Sevice.
So, is there any sollution?