[R] error : unused argument(s) when boxplot

[Pauline Haleux (JIC)]

Dear all,

I am a total beginner in R, so sorry if this is the wrong place. I am using R 2.10.1 on a Mac (Mac OS 10.6.2). 
I have this small dataset :
growth	sugar
75		C
72		C
73		C
61		F
67		F
64		F
62		S
63		S
I have no problem reading the table, or getting the summary, but if I try boxplot(growth~sugar, ylab="growth", xlab="sugar", data=Dataset), I have the following error : ERROR:  unused argument(s) (sugar).

Any suggestions ?

Thanks a lot,

PH