"addNodes.MBnetwork" <-
function(x,N,Names=NULL)
  {
    isValid <- validObject(x)
    x@N <- x@N+N
    if(is.null(Names))
      Names <- rep(NA,times=N)
    x@Names <- c(x@Names,Names)
    States <- as.integer(rep(NA,times=N))
    x@States <- c(x@States,States)
    Cpds <- matrix(nrow=2,ncol=N)
    x@Cpds <- cbind(x@Cpds,Cpds)
	Counts <- matrix(nrow=2,ncol=N)
	x@Counts <- cbind(x@Counts,Counts)
    Margs <- matrix(nrow=2,ncol=N)
    x@Margs <- cbind(x@Margs,Margs)
    Pvals <- rep(NA,times=N)
    x@Pvals <- c(x@Pvals,Pvals)
    isValid <- validObject(x)
    return(x)
  }