[R] Example(chron) doesn't work

[Vittorio]

Under R 2.3.1 for Windows (win xp) issuing

> example(chron)

gives:

chron> dts <- dates(c("02/27/92", "02/27/92", "01/14/92", 
    
"02/28/92", "02/01/92"))
Error in dates(c("02/27/92", "02/27/92", 
"01/14/92", "02/28/92", "02/01/92")) : 
        no direct or inherited 
method for function 'dates' for this call
> dts<-dates(c("02/27/92", 
"02/27/92", "01/14/92","02/28/92", "02/01/92"),format="%m/%d/%y")
Errore in dates(c("02/27/92", "02/27/92", "01/14/92", "02/28/92", 
"02/01/92"),  : 
        no direct or inherited method for function 
'dates' for this call
>

What should I do?
Thanks
Vittorio