Exclude missing values on only 1 variable

Hello,

I have many hundred variables in my longitudinal dataset and lots of
missings. In order to plot data I need to remove missings.

If I do

data <- na.omit(data)

that will reduce my dataset to 2% of its original size ;)

So I only need to listwise delete missings on 3 variables (the ones  
I am
plotting).

data$variable1 <-na.omit(data$variable1)