I've been given a wsdl file, and used the the WSDL.exe generator to make a
proxy file. I've then added the code for the web method, and compiled and all
is fine. I had to add in a load of namespaces for the web service to work
properly, but there is still an underlying problem. If I send it an XML file
with

<tns:Sales Order>

it doesn't work - I get an "Object reference not set to an instance of an
object". However if I send it <Sales Order> then this is fine. Sorry, I
realise my grasp on this is pretty weak, but have come up against a brick
wall. I've pasted in the code below.

Many thanks in advance.

------------------

namespace Warehouse
{
using System.Diagnostics;
using System.Xml.Serialization;
using System;
using System.Web.Services.Protocols;
using System.ComponentModel;
using System.Web.Services;
using Warehouse.Code.BLL;
using Warehouse.Code.DAL;
   
/// <remarks/>
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Web.Services.WebServiceBindingAttribute (Name="FulfilOrderBinding",
Namespace="http://www.deloitte.co.uk/soademo/services/warehouse")]

[WebService(Namespace=" http://www.deloitte.co.uk/soademo/messages")]
public class FulfilOrderService :  System.Web.Services.Protocols.
SoapHttpClientProtocol
{
 [System.Web.Services.Protocols.SoapDocumentMethodAttribute("replace with
soap operation url", Use= System.Web.Services.Description.SoapBindingUse.
Literal, ParameterStyle=System.Web.Services.Protocols.SoapParameterStyle.Bare)
]
 [return: System.Xml.Serialization.XmlElementAttribute
("FulfilmentRequestSummary", Namespace="
http://www.deloitte.co.uk/soademo/messages")]
 
 [WebMethod]
 public FulfilmentRequestType FulfilOrder([System.Xml.Serialization.
XmlElementAttribute (Namespace="http://www.deloitte.co.uk/soademo/messages")]
SalesOrderType SalesOrder)
 {
  FulfilmentRequestType fulfilmentRequest;
  int fulfilmentRequestID;
  int statusID;
  bool sufficientStock = true;
  SQLDataAccessLayer dataAccessObject = new SQLDataAccessLayer();
  fulfilmentRequest  = new FulfilmentRequestType();
 
  for(int i=0; i<SalesOrder.lineItems.Length ; i++)
  {
   int productID = SalesOrder.lineItems[i].productID;
   int quantity = SalesOrder.lineItems[i].quantity;
   if(!dataAccessObject.isStockSufficient(productID,quantity))
   {
    sufficientStock=false;
   }
  }
  int orderID = SalesOrder.orderID;
  if(sufficientStock)
  {
   statusID = Globals.UNFULFILLED;
   fulfilmentRequestID = dataAccessObject.GenerateFulfilmentRequest(orderID,
statusID);
   fulfilmentRequest.fulfilmentRequestID = fulfilmentRequestID;
   // this code has been superseded:
   // the shipping request ID is appended to the end of the fulfilment
request ID
   // so we need to remove the prefix: FFyyyymmdd (10 chars, so remove from
index 11)
   //int fulfilmentRequestID = Int32.Parse(fulfilmentRequestID.Substring(10))
;
   for(int i=0; i<SalesOrder.lineItems.Length; i++)
   {
    int productID = SalesOrder.lineItems[i].productID;
    int quantity = SalesOrder.lineItems[i].quantity;
    dataAccessObject.ReduceStock(productID, quantity);
    int orderLineNo = i+1;
    dataAccessObject.InsertOrderline(orderID, productID, fulfilmentRequestID,
orderLineNo, quantity);
   }
  }
  else
  {
   statusID = Globals.INSUFFICIENT;
   //fulfilmentRequestID = dataAccessObject.GenerateFulfilmentRequest
(orderID,statusID);
  }
 
  fulfilmentRequest.dateCreated = DateTime.Now;
  fulfilmentRequest.status =  statusID.ToString();
  return fulfilmentRequest;
 }
       
 /// <remarks/>
 public System.IAsyncResult BeginFulfilOrder(SalesOrderType SalesOrder,
System.AsyncCallback callback, object asyncState)
 {
  return this.BeginInvoke("FulfilOrder", new object[] {
                SalesOrder}, callback, asyncState);
 }
       
 /// <remarks/>
 public FulfilmentRequestType EndFulfilOrder(System.IAsyncResult asyncResult)

 {
  object[] results = this.EndInvoke(asyncResult);
  return ((FulfilmentRequestType)(results[0]));
 }
}
   
/// <remarks/>
[System.Xml.Serialization.XmlTypeAttribute(Namespace="
http://www.deloitte.co.uk/soademo/messages")]
public class SalesOrderType
{
       
 /// <remarks/>
 public int orderID;
       
 /// <remarks/>
 public System.DateTime dateCreated;
       
 /// <remarks/>
 public string status;
       
 /// <remarks/>
 public CustomerType customer;
       
 /// <remarks/>
 [System.Xml.Serialization.XmlArrayAttribute(Namespace="
http://www.deloitte.co.uk/soademo/messages ")]
 [System.Xml.Serialization.XmlArrayItemAttribute("lineItem", Namespace="
http://www.deloitte.co.uk/soademo/messages", IsNullable=false)]
 public LineItemType[] lineItems;
       
 /// <remarks/>
 [System.Xml.Serialization.XmlElementAttribute(Namespace="
http://www.deloitte.co.uk/soademo/messages ")]
 public AddressType shipToAddress;
       
 /// <remarks/>
 [System.Xml.Serialization.XmlElementAttribute(Namespace="
http://www.deloitte.co.uk/soademo/messages ")]
 public AddressType billToAddress;
}
   
/// <remarks/>
[System.Xml.Serialization.XmlTypeAttribute(Namespace="
http://www.deloitte.co.uk/soademo/messages ")]
public class CustomerType
{
       
 /// <remarks/>
 public int customerID;
       
 /// <remarks/>
 public string title;
       
 /// <remarks/>
 public string initial;
       
 /// <remarks/>
 public string familyName;
       
 /// <remarks/>
 public string emailAddress;
       
 /// <remarks/>
 public string homeTelephoneNo;
       
 /// <remarks/>
 public string mobileTelephoneNo;
       
 /// <remarks/>
 public string notificationChannel;
       
 /// <remarks/>
 public string notificationFormat;
}
   
/// <remarks/>
[System.Xml.Serialization.XmlTypeAttribute(Namespace="
http://www.deloitte.co.uk/soademo/messages")]
public class FulfilmentRequestType
{
       
 /// <remarks/>
 public int fulfilmentRequestID;
       
 /// <remarks/>
 public string orderID;
       
 /// <remarks/>
 public System.DateTime dateCreated;
       
 /// <remarks/>
 public string status;
}
   
/// <remarks/>
[System.Xml.Serialization.XmlTypeAttribute(Namespace="
http://www.deloitte.co.uk/soademo/messages")]
public class AddressType
{
       
 /// <remarks/>
 public string addressLine1;
       
 /// <remarks/>
 public string addressLine2;
       
 /// <remarks/>
 public string addressLine3;
       
 /// <remarks/>
 public string addressLine4;
       
 /// <remarks/>
 public string postcode;
}
   
/// <remarks/>
[System.Xml.Serialization.XmlTypeAttribute(Namespace="
http://www.deloitte.co.uk/soademo/messages")]
public class LineItemType
{
       
 /// <remarks/>
 public int orderLineNo;
       
 /// <remarks/>
 public int productID;
       
 /// <remarks/>
 public int quantity;
}
}