bgh11 <- read.fwf("C:\\data\\bgh11.txt", width=c(8,8,8),
 col.names=c("gender","trt","wtgain"))

attach(bgh11)

library(lawstat)

levene.test(wtgain[gender==1], trt[gender==1], "median")

levene.test(wtgain[gender==2], trt[gender==2], "median")