[R] Handling missing data

[premmad]

I have one column 
x
97
94
91
90
NA 
NA
NA 
NA 
I tried 
book$r<-ifelse(book$x!=NA,book$x+20,10)
I expect to get the result as follows
107
104
91
90
10
10
10
10
But what i was getting is empty column of variable r.How to solve this 

-- 
View this message in context: http://www.nabble.com/Handling-missing-data-tp25539335p25818365.html
Sent from the R help mailing list archive at Nabble.com.