R help - Mar 2014 - filter data

Hi,
This is not clear.? May be this helps:
dat <- read.table(text="cid cname
?101 us
?102 uk
?103 gm
?104 NA
?105 SA
?106 fr
?102 us
?104 fr
?105 gm
?101 uk
?102 us
?106 SA
?103 gm
?105 SA
?101 us
?106 fr",sep="",header=TRUE,stringsAsFactors=FALSE) 
?lst1 <- split(dat,list(dat$cid,dat$cname),drop=TRUE)
lst1[[3]]
#?? cid cname
#3? 103??? gm
#13 103??? gm

A.K.


hi users,
how to filter in cname wise and cid wise useing function  plz......give me some
idea's
cid cname
101 us
102 uk
103 gm
104 NA
105 SA
106 fr
102 us
104 fr
105 gm
101 uk
102 us
106 SA
103 gm
105 SA
101 us
106 fr