"validMBdataDE" <-
function(object)
  {
    if(is.null(object@N) || is.na(object@N) || (object@N < 0) || (object@N != as.integer(object@N)))
      paste("@N must be a positive integer",sep="")
    else if(is.null(object@n) || is.na(object@n) || (object@n < 0) || (object@n != as.integer(object@n)))
      paste("@n must be a positive integer",sep="")
    else if(!all(c(length(object@IDs),nrow(object@M),nrow(object@W)) %in% object@N))
      paste("Incompatible dimensions of some attributes (must all match @N)",sep="")
    else if(!all(c(ncol(object@M),ncol(object@W),nrow(object@design)) %in% object@n))
      paste("Incompatible dimensions of some attributes (must all match @n)",sep="")
    else if(!is.numeric(object@M) || !is.numeric(object@W))
      paste("@M and @W must be numeric",sep="")
    else if(!all(object@W >= 0,na.rm=TRUE) || !all(object@W <= 1,na.rm=TRUE))
      paste("@W must be between 0 and 1, or NA",sep="")
    else if(!all(object@design %in% c(-1,0,1)))
      paste("@design must only consist of either 0, 1, or -1",sep="")
    else if(!(object@lmMethod %in% c("ls","robust")))
      paste("@lmMethod can only be 'ls' or 'robust'",sep="")
    else if(is.null(object@prop) || is.na(object@prop) || !(object@prop >= 0) || !(object@prop <= 1))
      paste("@prop must be between 0 and 1",sep="")
    else
      TRUE
  }