[R] getting just the x or the y coordinate

[G.R.Nobles]

I have a data set (from GRASSGIS) I have imported it to R and I can 
get the coordinates by:
xy<-coordinates(data)

but I would like to have the x coordinates and y coordinates in 
separate dataframes x and y, does anyone know how to do this?

Thankyou
Gary
-----------------------
Gary R. Nobles
PhD Candidate
Institute of Archaeology
Poststraat 6
Groningen University
The Netherlands
Personal Webpage:

Project Website:
www.singlegrave.nl
G.R.Nobles at rug.nl