Ok, so I can't seem to find decent Windows Azure examples. I have a simple hello world application that's based on this tutorial. I want to have custom output instead of JSON or XML. So I created my interface like:

[ServiceContract]
public interface IService
{
    [OperationContract]
    [WebInvoke(UriTemplate = "session/create", Method = "POST")]
    string createSession();
}

public class MyService : IService
{
    public string createSession()
    {
        // get access to POST data here: user, pass
        string sessionid = Session.Create(user, pass);
        return "sessionid=" + sessionid;
    }
}

For the life of me, I can't seem to figure out how to access the POST data. Please help. Thanks!