search for: obstab

Hi all, I'm new to R, but have got the task to translate a short program written for S-plus. I am now stuck on a command twobin which does not seem to be available in R. Anyone know a replacement for this? The syntax used for this command in my code is: zobs<-twobin(obstab[1,1],obstab[1,2],obstab[2,1],obstab[2,2],0.05) where obstab is a two by two contingency table and the command produces an object (?) with, among other things, a chi2-value. Any and all help would be appreciated! Ulf