private static void Foo()
{
  while (condition)
  {
    NetIncomingMessage im;
    while ((im = s_server.ReadMessage()) != null)
    {
      // handle incoming message
      switch (im.MessageType)
      {
    case NetIncomingMessageType.DebugMessage:
    case NetIncomingMessageType.ErrorMessage:
    case NetIncomingMessageType.WarningMessage:
    case NetIncomingMessageType.VerboseDebugMessage:
    case NetIncomingMessageType.StatusChanged:
    case NetIncomingMessageType.Data:
        // incoming message from a client
        string chat = "";
        switch ((PTypes.PacketTypes)im.ReadByte())
        {
                  case PTypes.PacketTypes.Sync:
          {
             //Some action
                     ...
                     break;
          }
                        ...
                        ...
         }
    }
      }
   }
}