OnMarketDepth getting the offer size

[GKonheiser]

would this be correct for checking if anything has changed on the Bid or Offer when using OnMarketDepth?

if ((e.MarketDataType == MarketDataType.Ask || e.MarketDataType == MarketDataType.Bid) && e.Operation == Operation.Update )

and how would I check the bid size for the 2nd or 3rd best bid in the book?


Thanks