3/24/00   mle.alt.s  
          change lines 2 and 3 from 
          
            loglik <- c(NA, nlocus)
            messages <- c(NA, nlocus)

          to

            loglik <- rep(NA, nlocus)
            messages <- rep(NA, nlocus)

          Thanks to Marina Alexandersson for noticing a problem.
          Also, the `examples' were fixed in mle.alt.s,  mle.null.s,
          and lod.plot.s so as to draw in the correct data files.