I am trying to establish a Web Service for my Business Central Cloud.

I have this SOAP request:

 <s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
<s:Header>
    <Action s:mustUnderstand="1" xmlns="http://schemas.microsoft.com/ws/2005/05/addressing/none">http://tempuri.org/AmirCustomer/saveCustVend</Action>
    <h:CallContext xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:h="http://schemas.microsoft.com/dynamics/2013/01/datacontracts">
      <h:Company i:nil="true" />
      <h:Language i:nil="true" />
      <h:MessageId i:nil="true" />
      <h:PartitionKey i:nil="true" />
    </h:CallContext>
  </s:Header>
  <s:Body>
    <saveCustVend xmlns="urn:microsoft-dynamics-schemas/codeunit/AmirCustomer">
      <_custVendDC xmlns:d4p1="http://schemas.datacontract.org/2004/07/Dynamics.AX.Application" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
        <d4p1:AccountNum>12345</d4p1:AccountNum>
        <d4p1:Active>No</d4p1:Active>
        <d4p1:BusinessUnit i:nil="true" />      
        <d4p1:CostCenter i:nil="true" />
        <d4p1:Currency>TRY</d4p1:Currency>
        <d4p1:CustClassificationId i:nil="true" />                                  
        <d4p1:CustGroup>YD_KURUM</d4p1:CustGroup>
        <d4p1:Donem i:nil="true" />
        <d4p1:ElectronicAddress />
        <d4p1:HospitalCode>MED</d4p1:HospitalCode>
        <d4p1:PostalAddress>
          <d4p1:PostalAddress>
            <d4p1:Country>TUR</d4p1:Country>
            <d4p1:County i:nil="true" />
            <d4p1:RoleType>Invoice</d4p1:RoleType>
            <d4p1:State />
            <d4p1:Street>A Delaware, USA Company,Offices Located at 7600 Corporate Center Dr #500, Miami, FL 33126 USA,</d4p1:Street>
          </d4p1:PostalAddress>
        </d4p1:PostalAddress>   
        <d4p1:TaxGroup>YI_FTR</d4p1:TaxGroup>
        <d4p1:TaxOfficeName i:nil="true" />
       <d4p1:VATNum i:nil="true" />
       <d4p1:ValueStream i:nil="true" />
<d4p1:VendGroup>Null</d4p1:VendGroup>
      </_custVendDC>
    </saveCustVend>
  </s:Body>
</s:Envelope>

and this is my CODEUNIT:

codeunit 50104 "AmirCustomer"
{
    [ServiceEnabled]
    procedure saveCustVend(var _custVendDC: Text): Text
    var
        CustVendRecord: Record "Customer";
        ResponseText: Text;
        AccountNum: Text[20];
        Active: Boolean;
        Currency: Text[10];
        CustGroup: Text[20];
        HospitalCode: Text[10];
        IsCustomer: Boolean;
        IsVendor: Boolean;
        Name: Text[100];
        PaymTerm: Text[10];
        TaxGroup: Text[10];
        text: Text;
        xmlDoc: XmlDocument;
        Node: XmlNode;
        Nmgr: XmlNamespaceManager;
    begin


        if XmlDocument.ReadFrom(_custVendDC, xmlDoc) then
            error('Format(xmlDoc)');

        if XmlDoc.SelectSingleNode('//d4p1:AccountNum', Node) then
            Node.WriteTo(AccountNum);

        //ERROR(AccountNum);


        exit(AccountNum);
    end;
}

For now, I would just like to be able to pass AccountNum and other nodes to my codeunit for further processing…

With this current code I get the error:

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
    <s:Body>
        <s:Fault>
            <faultcode xmlns:a="urn:microsoft-dynamics-schemas/error">a:System.Reflection.TargetInvocationException</faultcode>
            <faultstring xml:lang="en-US">Namespace Manager or XsltContext needed. This query has a prefix, variable, or user-defined function.</faultstring>
            <detail>
                <string xmlns="http://schemas.microsoft.com/2003/10/Serialization/">Exception has been thrown by the target of an invocation.</string>
            </detail>
        </s:Fault>
    </s:Body>
</s:Envelope>

Any help is very much appreciated.

Thanks in advance,
V.