Exception thrown when .Net client calls Axis webservice

[Dhananjayan_K]

Hi,
When iam calling a webservice running in Axis from .Net client iam getting
the following exception:

An unhandled exception of type 'System.Web.Services.Protocols.SoapException'
occurred in System.Web.Services.dll
Additional information: java.lang.NullPointerException
An unhandled exception of type 'System.Web.Services.Protocols.SoapException'
occurred in System.Windows.Forms.dll
Additional information: java.lang.NullPointerException

Iam perform two operations  :
1. First i invoke addEntry to add a new purchaseorder
2. Second call the getOrder() method which will return purchaseorder type

The first operation goes fine..but the second fails..when calling from .Net
Both the operations works fine when called from java client...

My deploy.wsdd is like the following...
<deployment
    xmlns="http://xml.apache.org/axis/wsdd/"
    xmlns:java="http://xml.apache.org/axis/wsdd/providers/java">
  <service name="GetPO" provider="java:RPC" style="rpc" use="encoded">
      <parameter name="wsdlTargetNamespace" value="urn:GetPO"/>
      <parameter name="wsdlServiceElement" value="POservice"/>
      <parameter name="wsdlServicePort" value="GetPO"/>
      <parameter name="className" value="GetPO.TestingNetSkeleton"/>
      <parameter name="wsdlPortType" value="PurchaseOrderBook"/>
      <parameter name="allowedMethods" value="*"/>
      <parameter name="scope" value="session"/>

 <typeMapping
        xmlns:ns="urn:GetPO"
        qname="ns:purchaseorder"
        type="java:GetPO.Purchaseorder"
        serializer="org.apache.axis.encoding.ser.BeanSerializerFactory"
        deserializer="org.apache.axis.encoding.ser.BeanDeserializerFactory"
        encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"
      />
  </service>
</deployment>

thanks in advance...