Problem with WCF custom behavior used in the silverlight client

Question

To pass the culture information from client to WCF service, I have created a custom behavior using the custom inspector. The inspector class implements IDispatchMessageInspector and the IClientMessageInspector.

My client is the silverlight application. And now I'm facing the problem with the IDispatchMessageInspector since it's not available in the System.ServiceModel.Dispatcher.dll is not available to add as an assembly reference to Silverlight 4 project.

Can someone help me out ? How to handle the custom behavior to send message from SILVERLIGHT to wcf. ?